Connect fleck metal bypass valve to rheem rhs32 softener

[Bbembe]

Hi- I recently bought a house that has a fleck metal bypass valve plumbed in for the water softener connection. I have a rheem rhs32 softener that came with a plastic bypass valve that exposes male threaded ends. What’s the best way to make the connection between the two? Can the fleck valve be used or will it need to be cut off and something else soldered on? Thanks