You must have missed the myriad results when you did a search to help yourself. Maybe your browser sin't working properly
I found a few sites inside 30 seconds.
The work won't be stunningly cheap, but there are plenty o foutfits out there who would replace a crystal for you - even if it needed custom trimming/making.
Here's a few I found:
http://www.crystalfit.co.uk/
DIY - but you need to source a crystal: http://forums.watchuseek.com/f365/diy-guide-how-change-your-own-watch-crystals-174080.html
http://handycrowd.com/how-to/personal-stuff/replace-broken-crystal-on-rolex-watch/
http://www.watchrepairshop.co.uk/watch-glass-replacement/
http://www.clockparts-uk.co.uk/contents/en-us/d133.html
XXXXX, October 2015