If Cell is X then Value of the Cell to its right will be Y, across entire column in VBA Excel

Hi I am new to VBA and am having trouble finding the solution to what I'm trying to do.

I have 2 columns

Lvl1 Lvl2
A - - X
A - - X
A - - X
B - - X

If Lvl2 is "X", then I want it to be replaced by the same value as Lvl1. So from first to third row, Lvl2 would be "A", and in row 4 Lvl2 would be "B".

Another way of seeing this woud be if Lvl1 is A, then Lvl2's text would be A as well. If Lvl1 is B, then Lvl2's text would be B, etc.