You can:
1. Just remove the IR filter (LP2). As Glen already mentioned leaving LP1 may lead to possible slight loss of sharpness.
2. Remove LP1 and LP2. That's what I did with my 1200D. No need to even install the frames back.
3. Replace the LP1 with glass. Astronomik MC clear is the one to use. I am doing this on my 450D but only because it will be cooled to zero and I want to prevent fogging of the sensor.
My suggestion, go with option 2 and remove everything