Check the financial responsibility rules for Texas. If the state allows discontinuation of insurance, the carrier usually accommodates.
You can't do this everywhere. In Oklahoma for example, in order to discontinue liability coverage, I must re-tag a vehicle as "not used on highway." The tag fee is the same as if I were using it, and the increment is a year.
Of course, some operators self insure, rather than paying premiums to an insurance company. Here, we can post a bond for liability coverage to comply with the financial responsibility law.