You should have gotten instructions w/your lamp post. If not, contact the MFGR of the post.
Other than that, I/we would need more info as to what the 'base' of the lamp post is AND what do you have for a driveway.
My best to ya and hope this helps.
Jay J -Moderator
PS: Don't be afraid to give more info. You didn't give 'us' much to work with ...