Not sure what to do with a rock

[CoralBlue]

Hi all, when I setup my 16g biocube (7months). I picked up some carib sea liferock, not sure on the amount. Theres a large rock that is probably a foot by 6 inches and its flat on the bottom with rockwork on top. I'm losing a lot of sandbed that my yellow watchman would probably appreciate. Any ideas on how to get this rock off the sandbed? Breaking it up and slowly removing wont work, small sump on biocube, I've thought of attaching it to the backwall but have heard this can be a bad idea. Any help would be much appreciated.

 

[Sick_man]

Provide pictures of the tank, rock, and etc

 

[Anubisxii]

The goby might like digging under it, but pictures would be best.