Sunroof of my 03 XJR is not working

Dear all,
I’m just new to here and wonder if anyone can advise what to check: the sunroof of my 03 XJR can only flip-up but CAN’T open at all. Or how much I should expect if I need to change it with a new one?
thanks a lot!

This may help:
Also visit

Typo sorry this is the site I meant:

Okay thanks a lot, I’ll go browsing the website.