Change the flow of your loop at the pump end, that's what i did. Otherwise, no, you'll have to partially drain and switch them over.
This is what I was thinking, my plan was to drain the res with a syringe before I start but as the pump is not the highest point will the rest of the water in the loop not just flow back down the pipes when I disconnect them? By the way slight update, I have NO IDEA why, but I have gone on today and my temps are about 10C better, between 55-60 at full load. No....Idea.
)