Sounds like your lacking slightly in the mechanical skills (No insult intended here) take it to the mechanics and pay to get it done right, then if it stuffs up again in a month you can take it back to them and they should do it for free under warrenty. Somtimes parting with cash is hard to do but I always run with;
"The longest way round is usually the shortest way out!"
A rule that I always live by and most often save a heap of time and agrovation.