There are 6 bolts to hold the flywheel/flexplate in place and 3 bolts to hold the torque converter to the flywheel/flexplate.
I clean up the area with 1 part Dawn , 3 parts water and a stiff brush . Be careful cleaning near the transmission front seal and the engine rear main crank shaft seal.


The rear main seal area

 

Would that flexplate work?

 

According to part numbers from Rock auto, it's the same if the Terrain has a 4 cylinder engine, the 6 cylinder is different.

But it's the seller that's going to guarantee fitment, so your question should go to them.

 

Yes provlded it’s from a 2.4 l as it appears it is , note three kidney shaped holes, the v6 plate has 4



This is the V6 flexplate, note the 4 holes

This is your 2006 flexplate , 3 holes

This is the same 3 holes and same part number