having never used "i" in row reductions before here is what i would do (even though its kind of a pain).

First step...(other steps are of a similar for)

"replace -->"

For the first column this should give which should simplify to which is

Just "swap" places with their coefficients and multiply by the other row and put a negative sign in front of the second row. Notice how this works with fractions too (you have done the same thing with fractions before i would guess just didnt realize this applies here). By multiplying this way you get things to cancel nicely. This should work, but there may be a better way. Hope this helps and good luck.