I suppose technically it could be done, but not realistically. You will have to fully compress both springs at the same time to get to the bottom of the lock nut, then you will have to hold that nut to remove the top part, release the suspsension and pull the springs out. I think it could be done, but you're gonna get oil all over your bike in the process. I think you'll find that once you remove the big hex on top of the forks, and begin to compress the forks without draining them, I think oil is gonna come out.
Either way, you're gonna have to buy oil cause you will lose some.