My (US) SA Tivos require the use of a Torx screwdriver bit.

You buy just the bits that fit in those hexagonal shaped interchangeable bit screwdrivers.

Or you buy a Torx screwdriver of the right size.

I use the former type and the bit I use is marked "T10H" .

According to Tigers MFS 2.0 howto, you need a Torx #10 screwdriver.