You could make the split in different ways
Make a zero offset surface of both core and cavity side of the part (wothout the minor groove feature and blend), extend upto the common parting surface level. Create a parting surface (same level of the flat face).
Create mold tools folder and place there.
Create a sketch for the outer size and do a tooling split
or you can use the mold tools to make these parting line, parting surfaces and continue with the split (need to modify both core/cavity surfaces using surface tools)
I think this is fairly a simple part to split