It's remarkably easy to remove the front seats on a Mk1 Golf.
There are 2 plastic covers, one for each seat, that conceal the guide rails. They are on located in the rear seat foot-wells, abutting the transmission tunnel.
Gently unclip these.
At the front and center of each seat there is a bolt held in place with an acorn nut. These act as a kind of stopper to stop the seat from be moved back too far.
Simply undo the acorn nut and remove the bolt.
With the stopper nut and bolt removed simply pull the lever and slide the seat back as far is it will go.
The seats have 3 guides, or 'feet', like a tripod, that fit into 3 guide rails. By sliding the seat back, the two rear guides will slide out of the guide rails, allowing you to move the seat up and out.