DIY Doctor UK DIY Forums

I have purchase a steam shower and have assembled the shower up to fitting the seals for the glass. However I am having difficulty in getting the seals to fit snuggly against the glass and the frame. The seal has three ridges and I am able to insert the seal so that two ridges catch but am not able to push the seal in far enough for the third seal to catch.
I have tired using a flat blade screwdriver to push the seal in but am worried that if I put to much pressure on the seal with the screwdriver it will damage the seal.

Any advice would be gratefully appreciated.
Thanks