I admire your tenacity.
I generally consider the warning "No user servicable parts inside" to be a dare that simply must be tested.
But, I would not attempt this one...
For one thing, Dremel makes sparks, which could be bad.
I do not know enough about the internals to say it can't be done, but I would also imagine the seals are very tricky.
Best of luck.
1986 300E 5-Speed 240k mi.