To factorize the expression (3a-1) - 6 + 2, we can follow these steps:

Step 1: Simplify the expression inside the parentheses. (3a-1) - 6 + 2 becomes 3a - 7.

Step 2: Group like terms together. The expression 3a - 7 has no like terms, so we can skip this step.

Step 3: Factor out the common factor, if any. In this case, there is no common factor to factor out.

Therefore, the expression (3a-1) - 6 + 2 is already simplified and cannot be further factorized.