[Asus A636N French] How To backup WM5 and upgrade to WM6 ?

[Benka35]

Hi everyone!

I have an old Asus A636N PDA. It is under WM5 French.

I'd like to test WM6.

Is it possible?
Is it useful?
Is there any bugs?
Is there a way to downgrade to WM5 in French if I encounter problems?

Thank you for your help!