Soldering
 

Hi I've just picked up a second hand esc with wires but the are bit short can I just solder wire to it to get the right length or am I better to de-solder n solder the right length .please not my soldering ain't great thanks for any advice

better to de solder, use a solder sucker or braid helps, be careful not to over heat the esc I know the heatsink will draw a lot of heat away so if you don't wanna risk it which I wouldn't do if your not upto soldering much.
Safer to pop on some banana connectors and heatshrink, keep wire gauge the same.

Take it to a local club race there is surley someone who can do that for you.

De-soldering
 

Just a pointer that I only recently learned, some esc's warranty is void if you de-solder the original wires :(. I was advised that if they were too short for my layout was to put a connecter and extend the wires to achieve the length I needed:thumbdown:.

This is due to the heatsink drawing the heat through the mother board and overheating components.

:yawn::yawn::yawn: They just LOOVE to make money out of us

Enjoy

If it's second hand you won't have much or any chance of a warranty claim,
What make is it ? Some come with solder cups/tags to do your own. It's really not difficult you just need a hot iron some flux and solder. A wet sponge is handy to clean the iron tip on.

It's a speed passion esc I've already done but you don't get a lot of room .some one said but putting banana clips on n heat seal em how strong is this as it's going in a sx3 ?

Banana clips? Not sure what they mean but probably not strong enough. The room issue is the same for most ESCs.
If it's all wires too short remove and start again, if it's just 1 lead you could use a corally plug/socket in line heat shrunk with the extension you need but this removes flexibility.
I have quite an expensive Gas Iron as its used at work but have been very impressed by the Aldi, Lidl sub £5 jobs

Dazzler an sx3 is a bit hard if you want a tidy job with all the belts in the way,yeah use banana connectors but def insulate em properly, if your uncertain about damaging the esc dont risk it, pay a few quid on the connectors at least this way you can run the esc and make the right adjustments later when you or someone else can do the job the way you want it.

Get some short 3.5 mm male and female and a bit of heat shrink ;)

Thanks guys for your help . Your right it is very tight mate