Hubby is too disabled to do anything, so I plan to try to replace trap and drain pitted icky flange on wall hung lavatory in small half bath. Problem is, I can't figure out how to remove the flange. I removed stopper from pop-up assembly...am I going to need a special tool?

(I found some funny lookin' pliers in his tool chest with points going out; they spread open when squeezed- will they work?)

Our home is over 40 years old so have sprayed connections/joints with WD-40 in hopes that will help loosen them.

Suzi