Breaking screwdrivers when changing Cartier strap

[Phrank308]

I am attempting to remove the four screws which hold on the strap of a Cartier Tank Louis. This watch has a hollow tube which fits inside the strap and small screws attach to it through the lugs. The AD gave me instructions for the strap’s removal which call for using a 80 screwdriver. So far I've snapped two Horotec T profile tips, one when I first changed the strap and another now when trying to change it back. I noticed there as a bit of space available when using the size 80 so I purchased a 90 screwdriver while picking up replacement tips. The 90 is a "normal" profile. I've managed to bend the edges of two of these so far, not majorly but enough to cause them to "ramp" the driver out of the slot. I figure I must be doing something wrong to bend steel screwdrivers with a gold screw. There is a bit of "slop" when the screwdriver is engaged, as though its not filling the entire width of the screw slot. I was able to remove one screw and confirm that the bit reaches the full depth of the screw slot. 

Any advice on what I may be doing wrong?   Should I step up to a size 100 screw driver (I think there is room) and if so is normal to T profile preferable? I’m a complete novice at this type of work so please don’t assume any knowledge beyond which end of the screwdriver I should be using.

Thanks!

[jdm]

Have you heated the spot to loosen the locking agent? 

[Phrank308]

I have not. I’m not sure how I would do that with risk to the band (alligator). Would i need to use something like a fine soldering iron?

[jdm]

Yes that will be perfect. Just FYI there are torque knob driver for bracelets.

Edited March 8, 2020 by jdm