So if you did want to do it yourself you’ll probably need some of the following-
Fox fit cartridge bleed tool 803-00-276 £20
Fox 36mm dust wipers 803-00-933 £29.60
Fox 10wt green oil 025-03-008 £17.23
Fox 10wt red oil 025-02-003 £26.23
Plus the bladder obviously which used to be available in a service kit for the 36 fork 803-00-685 but I think that p/n has been superseded now and the bladder is also available on its own.
All that assumes a 36 fork, although I think the bladder is common?
To strip the damper side down and replace the bladder will also need a clamp set to hold the damper rod in a vice, this is about £98 from fox.
Mojo and tftuned will do the work, I should think it’d be the service price plus the cartridge rebuild cost? I’ve had better service from mojo recently but previously tftuned have been very good so ymmv.