Hi,
changing the screenwash bottles really easy, all you need is a 10mm socket, socket wrench and a few extensions for your wrench
however... i doubt your bottle would be broken unless you've been in a smash...
i had a mystery leak of wash fluid and after a good few months managed to narrow it down to a tiny little o-ring/washer missing from the little connector which connects the hose to the pump which is fitted to the wash bottle
the easiest way to 'diagnose' this would be to remove the fog light cover (drivers side), fill your wash bottle with about a litre or so of wash fluid and whilst you watch through the fog light opening, get a helper to pull on the stalk to activate the pump... if its the o-ring you ought to see it quite clearly leak from the T-piece which joins the hose to the pump
part number for the 'angle piece' which includes the 'o-ring' is 3B0 955 665 C, i wouldnt recommend trying to replace the entire t-piece... just use a paper clipe to pick out the o-ring from the new t-piece and place that on the end of your t-piece and just push it onto your pump fitting
- if however it is your wash bottle then you've got to get yourself a replacement wash bottle - if you havent got headlight washers, i've got a bottle here complete with pump you can have for cheap