How do I remove the rear foot rest on a Kawasaki er6f? There is a central pin with a circlip to hole it in but after the circlip is removed the pin won't come out.

This will depend on the year, model and trim options fitted to the bike. They will be held on in one of 3 ways. A Hex ('Allan Key') bolt, a Torx head bolt or an 'External' Circlip (snap ring). Could you comment below with a photo of both sides of the pin?
You will need a specific tool for each of these.The tools are cheap and easy to get.
The bolts unscrew like any type of bolt. You might need to hunt out the longer Hex and Torx tools. The Circlips need a set of pointed grips you use to ease the clips ends apart to slip it off the pin. The pin should then push all the way through and out the other side of the mount.

If I'm thinking about the right thing, the clevis that is attached to the rear brake lever that the rod that goes to the rear brake master cylinder connects to, the clevis should have a pin connecting it to the rear brake lever. On the backside of the pin is either a cotter pin or a circlip holding the pin in. You may have to take the rear brake lever off to access the circlip or cotter pin.

Good Luck
Steve

There are 2 circlips (1 on either side that need to be removed first. Then you can either use the special tool available in most tool shops or a bolt and 2 washers and piece of pipe, one washer must be smaller than the outside diameter of the gudgeon pin and the other must be bigger than the pipe. The pipe must have an inside diameter that allows the gudgoen to be pulled through it. You slide the bolt through the large washer then the pipe and then the gudgeon pin hole, then the small washer and then put a nut on the bolt that is slightly smaller thann the washer so it doesn't score the piston as you wind it and the gudgeon pin through the piston and into the pipe.

To remove/unlock the seat on a Kawasaki er-6f find a circular hole under the plastic seat fairing half-way along the seat on the left-hand side. Using the ignition key twist the lock set in the hole

if you can see from behind the speedo casing, there should be a hole where the 2 wire goes in. Now you must remove 2 or 3 screws that hold the 2 half piece and inside of it you will see the location next to speedo cable.

A circlip is basically a circular clip. There are two types, inside and outside. An outside circlip fits in a slot cut into the outside of a shaft. An inside circlip fits into a slot cut on the inside wall of a cylinder. Both types are "C" shaped with a small hole in each end of the opening. A special tool called a circlip remover has tiny hardened points that fit into the holes to either expand or contract the circlip for removal/installation. In engines I have seen circlip failures on the piston pin inside an engine to allow the piston pin to move. It could possibly let the piston scrape the inner cylinder wall and cause a grinding noise or worse. If not repaired, I doubt the engine will continue operating for long. Did they find a circlip in your oil after draining the oil?

the foot peg will have a pin going through it to attack it to the rear set and on the underside of the foot peg on the bottom of the pin there is a circlip this needs removing then you can tap the pin through removing the footpeg and return spring.