Find And Replace One Line At A Time

I find this data: X1 X2 X3 X4 X5
I replace to this: X2 X3 X4 X5 X6

I know I can "find and replace" one line at a time, But I want to do this-
I have 4 rows the same data:
X1 X2 X3 X4 X5
X1 X2 X3 X4 X5
X1 X2 X3 X4 X5
X1 X2 X3 X4 X5

I want to select all 4 rows at same time, (now, this is what I need help with is to end up with the following after using "find and replace" and adding 1 to each specific number without having to select and replace data one row at a time). If not "find and replace", how could this be done? In a nutshell I want to add 1 to each specific number as you go down the rows quick and easy.
X2 X3 X4 X5 X6
X3 X4 X5 X6 X7
X4 X5 X6 X7 X8
X5 X6 X7 X8 X9