I am removing my laundry cabinet. I have removed it except the drainage pipe highlighted in red in the attached screenshot. Could you please suggest how to open it? The pipe goes into concrete slab.
You will need to cut it off and lift the cabinet up over the stub that is left. A vibrating multitool works great or a reciprocating saw. You also appear to have enough room to even use a hand saw there.
You should evaluate the plumbing of your system when you replace the piping. There appears t be a few issues that should be addressed there.