Welcome to the forum.
Are you asking if you can convert a 75b compact (safety) to a decocker? If so sadly no.
Or if your one of the lucky ones to snag a surplus steel framed PCR, and want a ambi decocker, hmm, I?m not sure. One would think that an ambi from an SP01 Tactical maybe could be added with some fitting.
I?d give CZ Custom a call, they?d be able to answer your question.