Goto PM Hobby
http://www.pmhobbycraft.ca/store/ and talk to them. They probably offer services. Otherwise, soldering is not really rocket science. Make sure you have a good iron that is appropriate for your application, good solder, flux, and sponge. Talk to your friends, one of them is bound to be good at soldering. Most of mine are or have tried their hand at it.
If you have heat issues, try switching to low resistance wire.
I would recommend replacing the connectors as well with something like Deans connectors which you can also pick up @ PM Hobby or online. These are rated for much higher heat and amperage and pretty much the de facto standard for many electronics and RC hobbies.
