How to unscrew a very tight new plastic torch from its base

had a quick look online and found this is a museum piece.
http://www.flashlightmuseum.com/Eveready-Flashlight-FAB4DCM-Red-Black-Sea-Beam-Waterproof-Lantern-6V-2003
Called a Dolphin torch, I remember these from the '80s and had to replace the batteries too often to ever want to do it again.
The front unlocks by rotating 1/4 turn. The batteries are a 6V sealed lead acid cell and now cost more than a new modern torch with a Li-ion cell. You will need a 6V charger if the battery can be recharged and unlikely if its old and discharged for long time.

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The bezel (the circular portion on the front of the flashlight that holds the bulb and lens) will unscrew. The old battery should slide right out.

Hope this helps.

Twist the top of the torch.

You need to twist the black bulb end off in the direction of the arrow labeled open. The best way I found was to place the yellow end between my legs to hold it in place.

twist the top of the torch, the model I had was with 2D batteries.

Use extreme force to twist in direction of arrow.

Carefully.....

Check in the base of the torch and you will see the spare bulb. you need to pull the spring out to get at it.
Next unscrew the top off the torch to expose the bulb.
The bulb is easily removed by gently pulling straight out. Replace the new bulb in the same way, lining the two pins up with the holes (doesn't matter which way round) and wipe the bulb clean of any finger grease etc.
Screw the top back on and replace the spring in the base before screwing the base back on..
Replacement bulbs, and all other parts for that matter, are easily sourced at any good outdoor store that stocks MAG.

Hope this helps..