I'm a vehicle mobile glass fitter mate and would say it's more hassle than its worth to do on your own. Octavia screens are bonded in and are rather tightly bonded in at that, in my experience that is. This means it would need to be cheese/piano wired out in order to avoid breakage, or autoglass has a special ratcheting tool they use. I would advise asking your local mobile fitter and see how much they would charge to remove then pass the cost onto the buyer. The buyer will need to employ a fitter anyway as they will need someone to bond the screen to the next car so sensibly it would be an idea to put the two cars side by side and have a fitter come out to cut one out and stick it in the next.