I think there is something going on with that beta version of TIS. While the job number is correct, the contents of that link don't match up to M3 components. Try this link, which for me comes up with the repair for M3 diffs (and a much simpler procedure):
https://www.newtis.info/tisv2/a/en/e...th-lid/PeahQlD
I doubt any independent uses 100% of the specialty tools suggested by BMW for any particular job. I would bet that even most dealership techs skip using all of the special tools for every single job. It costs more time. This job can be done with off the shelf tools with the exception of removing the pinion nut which needs a thinner wall socket. You can spin the pinion nut off with an impact, pull the flange off with a generic puller, swap the seal like you would any other blind seal, and carry on. Would it be done to the same level of precision and accuracy as suggested by BMW? No but it would solve the leak for probably as long as you're going to own the car. That's how most indy's would do it, whether they tell you they use OEM tools or not...
Edit:
You cannot use typical bearing/seal drivers on that seal because the pinion protrudes out the front of the housing. Most would substitute a large deep well socket or piece of PVC pipe to drive it in without distorting it. The only caveat I can think of on this job if you're not going to use the special tools is to not overtighten the pinion nut when reinstalling the flange. If you overtighten it past the point it was tightened to originally, you will increase the pinion pre-load which will cause other major problems.