Okay, where to start...
Yes, you can't remove placed orbs, but this is not necessary. I.e. you can't lock yourself in.
There is a way down blocked by 2 doors, and 2 orb holders, that's the way you want to go. The first orb is easy to find (up and right), but the 2nd one requires you to go quite deep into the temple (the way is strightforward imho, just go past the corridor with the flashing energy barriers and follow the way along, on the way you'll see the orb/pearl, unreachable behind a pillar. To reach it from the other side, follow the way along further.
After you have opened these 2 doors, you may refer to
this topic.
From there, it is very quick to exit the temple.
(Slight spoilers: Oh and don't mind that last closed chamber and the red plant you will see just before getting out, it's for later)
Is that enough to get you out, or do you prefer screenshots?
