Does anyone have a munual for my circular saw?

A long while ago I was given a circular saw by a workman who said that the surface plate is warped and needs replacing. I assumed then that this was all that was wrong with it, but I couldn't switch it on. I have never used one before and haven't an instruction manual for it, therefore I do not know how to get it going. Do you have a manual that I can buy and can the surface plate be straightened or replaced?
It's made in China by Challenge model MCS5025.

Regards,