Instead of trying to break open the cassette with a jeweler's screwdriver, use a straight blade screwdriver that just fits the diagonal of the erase slot and give it a twist to make the initial break. Then use a thin bladed knife such as a dinner knife to workaround the shell casing. A dinner knife is not sharp , so it will not damage the tape if inadvertent contact is made. The handle of your tweezers would also work for that.
If the tape is really wrinkled, the tape can be ironed to flatten it. It takes patience and I use an iron designed for Monocote film to provide the heat.
Instead of trying to break open the cassette with a jeweler's screwdriver, use a straight blade screwdriver that just fits the diagonal of the erase slot and give it a twist to make the initial break. Then use a thin bladed knife such as a dinner knife to workaround the shell casing. A dinner knife is not sharp , so it will not damage the tape if inadvertent contact is made. The handle of your tweezers would also work for that.
What adhesive tape do you use, and where do you get it?
If the tape is really wrinkled, the tape can be ironed to flatten it. It takes patience and I use an iron designed for Monocote film to provide the heat.
Use an exacto knife