UPDATE: Neighbor offered me this unknown mandarin and orange tree for free but I have to remove them this weekend. It's hot. Any advice from those that have done it successfully?
Update: Turns out it was worth it, but for surprising reasons. Both trees were 100% rootstock, the second tree looked terrible up close and I immediately declined. The first tree was smaller than it appears in the photo and I dug it out fairly easily but cut two of the longer taproots. My reasoning was that I didn't care that much if it died but I'm not going to spend an hour and break my back digging it out in full sun. I pruned it nearly entirely of its canopy before digging out. I bagged all the fruit on it for seeds for future grafts. Then the old lady who was impressed by my citrus knowledge wanted to show me her other fruit trees in the backyard and she's no dummy, she's got practically an orchard of goodies. She let me take a bunch of cuttings from her amazing late blooming Washington navel, which i will graft to some young rootstock I have been growing. And then other cuttings from avocado and some others. All it all, it was a pretty easy task and well worth it. As for the rootstock tree surviving, no idea. But it's in shade and i gave it a light water with seaweed extract and molasses.