have you fitted the windscreen seal yet?
i've just done it and i put an realy thick bead of sealant on the seal, then carefully inserted the glass in the seal and then fitted the frame. easy peasy.
then you have to remove the excessive sealant, either when it has dried or immediately after you fitted the fram depending on the adhesive you use.
mine got a bit messy because i put to little sealant so i've had to add more after i've fitted the frame but it was easy to clean after it has dried with some thinner and plastic scraper.