Hi!
What do you want to do? Open and repair the fork legs? Or only remove the fork legs from brackets/triple tree?
Remove front wheel, caliper, fender, headlight (you can keep the headlamp in place, but you must prevent it from falling down after the headlight brackets are released from the fork)
Loosen upper and lower standpipe clamps, then it is possible to pull down and out the complete legs. Thereby the headlight brackets will come out. Triple tree remains in place. Possibly the rubbers in the chrome rings of the headlight brackets stick to the (rusty) standpipes, then release by turning.
Opening of the standpipes depends on model.
GT250A has a plug with o-ring and circlip at the top of the standpipe. No thread! The plug will come out after removing circlip only by pressure of the fork spring. In most cases it will jam in the circlip groove. To help it to come out, push it a bit down (with e.g. a socket wrench + extension) so that it lies aligned in its seat and can pass the groove.
After removing the plug the spring can be pulled out.
To remove the outer tube, remove front axle clamp, below it an allen screw is accessible, which must be loosen.
The threaded part (by Suzuki called: pipe seat, 51146-33130) inside the fork leg, in which the allen screw is seated, may rotate and the screw will not loose then. There was a special tool to counter the inner part: T-Handle: 09940-34520 + Attachment A: 09940-34530(-34531) You can buy it (e.g. from cmsnl.com) or create it yourself.
Until now I have managed without this tool, in this way:
Use the spring force to block the 'pipe seat' = loosen the allen screw before removing spring:
Hold the whole fork leg upside down on the ground (on a piece of wood or plastic, against damages). First, give the allen-screw head some hits, using allen-bit and hammer. Then use an impact wrench or an electric/cordless screwdriver to loosen the screw, while pressing the fork leg down 'into the spring' to increase the spring force.
At the older fork version up to model L with chromed threaded plugs at the top of the standpipes it is not necessary to remove the allen screw at the bottom in order to dismantle the outer tube.
After removing the circlip on the fork seal the standpipe can be pulled together with the sealing ring. The sealing ring is thereby pushed out by the 'inner tube guide' of the standpipe.
This requires some force. I remove the fork spring, then clamp the standpipe's upper end horizontally into a vice (with aluminum jaws). Then I push the fork leg together and with a jerk apart against the stop. The sealing ring slides out and the standpipe can be pulled out.
hope you understand my German accent
Markus