move shower drain with 45s?

I'm doing a bathroom remodel which includes converting the existing roman tub into a walk-in shower. I had a plumber install a new p-trap, riser, and drain to the level of the floor and then I filled in the tub with concrete. I definitely got ahead of myself and now realize that ideally the drain should be located about 8" from where it is now.

Is there any problem with demoing the concrete to the appropriate depth and using 45 degree elbows to get the drain in the right spot?

thanks for any help...Brett

Moving the drain with 45's should be okay.