Removed adblue tank, torx screws corroded - any idea how I can access the pump?

[Mexico14]

Have put wd40 but it hasn't helped.

[wheeler]

First you need to wire brush then to get the worst off, then get a fine pointed pick & scrape out the rust on the inside points of the screw, when trying to remove tap the socket into the head with a small hammer before trying to remove. You should get them out no problem.

[Mexico14]

9 out with 2 proving stubborn. Definitely helped using the halfords advanced t25 bit! I'll try your suggestion on the final 2.
Cant wait to see what lies beneath the cover...

[Mexico14]

Can't move those final 2 screws but could open the cover enough to see there's water in there.