In my experience with Campy cartridge BBs, teh drive side threaded end is very tightly attached to the main body, and the non-drive side slips on and off as on a UN55. On neither side do they thread onto the main body. I do not interpret that exploded drawing as implying the drive side cup is intended to be removable.

Bottom-line for Robertorolfo: I have always seen the Italian versions and BSC versions of their BBs to be indepently packaged and marked. They are not like a Phil, where many variations of cups can be applied to a smallish number or main body designs. If you have an Italian BB and to use the chainset you need instead to have a BSC BB that will fit, you need to find and buy one which is designed for BSC. I don't see any reliable process for swapping out the cups for cups with different threads. Looking at them I have often thought "these look like they should come off," but that doesn't mean I can get them off reasonably.

I also want to caution people about something I have seen in BF C&V several times: CAMPAGNOLO IS NOT NECESSARILY LIKE SHIMANO. If you started in mike mechanics from Shimano, this is an easy mistake to make. I started on Campy and on British bikes, so Shimano was the newcomer to my world. I have R&R these BBs probably 20 times on the bikes.

If you're going to try to muscle off the drive side cup, I can't say its not possible but be really careful. The cup is rather soft aluminum and it is the threaded part. You might ruin it. Then you have to buy a new one, I think they are all out of production, which means good used ones are priced at what the market will bear - anywhere from $30 each to >$200 each. And by destroying a perfectly good BB, you deprive another deserving bike nut of having the part. So: don't give bad advice, ask if you are not sure how to understand the instructions, and don't destroy the parts. Finally: don't lose the screws, hardware stores will not have direct replacements, and improvisation might be complicated