I want to know how to wire a speaker

here you go.
http://www.jumbosunshade.com/swd01.htm
make sure to figure out what the ohms are of each speaker and how it is currently wired before messing with it. Make a plan, then act.

Very simple. Remove all black screws at top and sides of cabinet. Gently slide the amp unit out (towards rear). Done! :)
Don't be alarmed if you have to "tug" on it a bit. This is normal. Just don't try to "FORCE" it out.

In a word, NO. The line out is line level audio... it has NO power amp and cannot drive a non-powered speaker. I have both of these cabinets myself. You need to use an amp with the non-powered speaker. When using an external amp you will need to make sure you phase the two speakers correctely... you could just reverse the speaker leads of the non-powered one if needed.

If you failed to turn off the amp before changing speaker cables you have fried something. Since the plug shorts when unplugging, if the amplifier were on, the amp would sense the short and will often fry the amplifier or the speaker. You don't mention what the amplifier was. If the speaker were daisy chained to other equipment a ground loop probably formed and blew out the woofer. The horn often has Peavey's "SoundGard" circuit so it probably survived. NEVER change speaker cables while amp is on. ALWAYS secure the 1/4 inch type cables through the handle of cabinets so they can'tbe inadvertenly pulled out and burn up equipment. Your amplifier driving one of these should be rated at no more than 200 watts RMS. These "400 watt Prrogram" ratings are for the birds... fake advertising. Put 400 watts into this RMS and it blows out.

Yes, you can put two 8 ohm speakers daisy chain per side MAX. The Speakon should have ONLY two wires on the +1 and -1 terminals unless you are using bridged mode which is NOT applicable in your configuration of speakers. Also be careful is you use any 1/4 inch speaker plugs in the sytem as the SLEEVE, not the TIP of channel A is the "hot" lead... get this to ground someplace and goodbye amp.

You best rewire the cabinet to put the two speakers in series. Wire one speaker plus to minus of the other and bring the other lead, one from each speaker to your jack on the cabinet. The amp output impedance is what is set on the switch... for two 8 ohm speakers you would use both jacks to the two speakers BUT ssince you have 4 ohm speakers the ONLY option is for two in series and set the switch to 8 ohms. The amp is ONLY 30 Watts so don't expect too much sound output... You should get a nice CLEAN sound at a reasonable level. If you drive the amp too hard it will clip and you will get garbage.

Yes, in bridge mode you will wire ONE Speakon that will have the two speaker wires connected to pins "1+" and "2+". You do NOT need the manual to do this, the info is right on the back of the PMP6000 itself. You will plug that Speakon into channel "B".

PLEASE note that you CANNOT go below 8 ohm speaker impedance. If your speakers are 4 ohm you MUST connect two in SERIES which requires special cables and the speakers MUST be identical. You can connect TWO 16 ohm speakers in parallel by daisy chaining, however 16 ohm speakers are NOT very common. With 8 ohm speakers you can connect EXACTLY one in bridged mode UNLESS you connect four of them in series-parallel which requires special cables and great care. Believe me you do NOT want to have an accident with this amp as repairing is extensive.

Lastly, put the speaker configuration switch down to the bridged mode.

This is how bridged mode works: Sliding the switch down basically configures the two power amps in monaural and one amp is inverted so there outputs are out of phase by 180 degrees effectively doubling the voltage.

Remember that BOTH wires in bridged mode are HOT and grounding one while amp is on will likely blow out one side or more.

The second jack which is present on MOST speakers is for daisy-chaining a second speaker. One has to make sure to NOT go below the minimum impedance allowed by your amplifier. Often this minimum is 4 ohms which allows TWO 8 ohm speakers to be connected to the 4 ohm output.

Some of the rocker switches can be PRIED out from the outside as they have plastic "springs" at the ends... look at you new one.

IF you can pry the old one out you MAY have long enough wires to allow the old one to come out a bit and transfer to new one and push it back in.

ELSE you have to take the amp out.

USUALLY the speaker and the board it sits on remains in the cabinet.

There will be screws that hold the amp in... You kind of have to try to find which to remove to release the amp chassis. You may have to remove the speaker wires or wires to a reverb tank... MARK ALL these and restore to exact same places.

HINT: Once the screws are out, OFTEN the Tolex cabinet covering loves to catch on the chassis so you have to fight to get the chassis out... a real pain and THEN putting it back in the Tolex fights you again !!!

Have a look at this web page:http://www.thegearpage.net/board/archive/index.php/t-275743.html Also this one:http://www.marshallforum.com/cabinets-speakers/1034-dating-marshall-4x12-cabinet-without-speaker-codes.html Hope this gives you some help.