Different variants of the transmission have different bolt patterns (also depending on whether the engine is a four, six, eight or twelve-cylinder model.
To get to the two top-most bolts at the top of the transmission, it is best to lower the rear end of the transmission an inch or two by removing the transmission (rear) mount. This allows the powertrain to tip backward on the motor mounts, and opens up a bit more room to access the top-most bolts. On the six-cylinder M104, I didn't find the top-most bolts to be inordinately difficult to reach; however tightening them was overall a bit more difficult than loosening them was.
If I remember correctly, there is one bolt on the driver's side at the top that is above the top-most starter bolt (so it would be at the 11 o'clock position) and there is one that is at the 1 o'clock position on the passenger side. To get at these, it is a very good idea to have a combination of 12-inch and six-inch extensions for a 3/8"-drive ratchet, along with a "wobbly" extension that allows access from an angle.
On my M104, I was successful at getting to all bolts from BELOW the car. I do not know if this is possible on the eight-cylinder M119 models, but I have heard that the top-most bolts can be accessed easier on the V-8s from ABOVE. Perhaps one of our technicians or GSXR can clarify/confirm this. All engine-to-transmission bolts are torqued to around the ~55 Nm level, if I remember correctly, on the M104.
When re-installing the transmission, it is exceedingly important to get things lined up properly. It's best when you get the transmission bell-housing generally aligned with the back of the engine block, to replace the bolts at the "3" and "9" o'clock positions first, and then insert the other bolts. These bolts are easily accessible (one of them on the M104 would be the bottom starter bolt) and easy to tighten. This will mate the two halves of the bell housing and block, and make for insertion of the other bolts easier. Do not tighten/torque the bolts until all have been inserted. I torqued mine down in a more-or-less cross-hatch pattern, not sequentially around the circumference of the bell housing.
Hope this helps.
Cheers,
Gerry