If you do want to save your excess and a claim against you, it can be done. Bear in mind that a windscreen claim has to be declared for 5 years if you change insurance company, and whilst your NCD remains intact, it does make a difference to your premium, no matter what they tell you! You get an insurance quote, then tell them you have had a glass claim in the last five years, see what happens... and don't ignore it, as all claims are logged on a central database.
The hardest bit is removing the glass without damaging it, but most decent scrapyards will remove them for you, or try eBay. The small quarterlights aren't too difficult, but you need the right tools. To remove the small windows, a cutting wire, handles and a wire inserter should suffice, and there are videos on youtube, etc., showing you how to use them. If you were cutting a glass out for reuse, you could do with practising first, but it doesn't matter if you are removing the old damaged one.
Carefully remove any plastic trims so they can be reused. Try to leave a thin skin of sealant on the car body, as any bare metal needs to be primed with the special primer. Carefully trim down the thickness of the old sealant after removing the glass, if required. Wipe the old sealant on the body and the glass with IPA or thinners and apply a proper polyurethane windscreen bonding adhesive such as Dinitrol or Mannol to the glass, or at a pinch, polyurethane seam sealer. Cut a 90° vee into the nozzle to guide application. Carefully fit the glass in place, taking care to set it in the same position as the original, and fix in place with tape until it cures.
It's a fiddly job, personally I would try to find someone who fits windscreens and ask how much they would charge to do the job if you supply a secondhand glass, it will still probably end up cheaper than your excess. I've done them before, but a friend of mine's nephew now works for one of the big national windscreen fitters and will fit a windscreen on the side for twenty quid!
