Transplant successful. Thanks for all your tips. Both PCs are running nice. No real hiccups along the way. 
Hi, I have an XPS 8700 purchased in 2014 that came with an added discrete AMD Radeon R9 270 installed. I would like to remove the AMD and use just the iGPU from the Intel i7-4790 but I'm concerned about being, well, a noob.  From what I can tell from the Device Manager, and from reading other posts, the iGPU have been disabled. Is it a just a matter of downloading the Intel drivers for the i7-4790 to run the iGPU? Should I do this after I remove the added dGPU or before and will the AMD drivers currently on the PC mess up the Intel drivers? Any suggestions would be extremely helpful! 
XPS 8700, remove added dGPU and switch to iGPU?