Hopefully there will be far less of them and IF the PT win an overall majority, or even with a MFP coalition, ALL of the senate will be kicked out and a new senate elected by the people will be installed.
Hopefully there will be NO seats reserved for the RTP, the military, the civil service or any religious body.
If that goes against the current constitution, then simply tear up the 2017 constitution and substitute it with the 1997 peoples constitution, suitably amended.
It is what the coup leaders do every time, so there is a precedent.