Had a search last night and the image you referenced is very common. Some youtube video that I did not look at.
There will be several ways to make a
simple colour change. None of them are beginner click-n-wish.
As an example. you can do this
Make some accurate selections - shirt - helmet - anything else you want to change.
(hint - save the selections as channels for use later on)
Desaturate the selected areas to create a suitable base layer preserving any shading.
Create coloured layers with layer masks.
The
Mode of these layers will alter the colour so experiment with alternative modes.
That gets a simple colour change. If you need to change any details such as numbers, logo's ... then it comes down to your artistic ability.
that example for you to play with:
http://www.mediafire.com/file/69ev1j3cju...ayer.xcfgz
That image is very small, 330x500 -ish. A larger image is easier to work on.