First things first, you want to identify whether or not you have a single end powered tube and non-shunted tombstones.
A simple way to make sure you have a single ended tube is to look for the L/N sticker at the end of the tube.
Since the single end powered tubes only use one side of the tube, both live and neutral power will be on the same side, but different pins.
It's important to identify this sticker so that you don't put live and neutral on the same pin or use shunted tombstones and end up like Marv....
The "L" indicates the pin that live power will go into.
The "N" indicates the pin that neutral power will go into.
Do I have shunted or non-shunted tombstones?
You should have received non-shunted tombstones with your package. If not head over here to order some complimentary tombstones.
If you choose to use your own tombstones simply make sure that yours are non-shunted like in the photo below:
If you have shunted tombstones remove them from the socket on the end where the live and neutral wires enter the fixture. Insert the non shunted tombstones and make sure they snap securely into place.
1) Remove or disconnect all of the wiring connected to the starter/ballast.
2) When removing or cutting the wires from the G13 socket at the end of the fixture that does not have power or the "dead" end, make sure that they are tight in the fixture and will hold your new LED bulbs securely.
3) If you elect to leave the starter, ballast, or cut wiring in the fixture or if it cannot be easily removed, make sure that all unused lead wires are wire-nutted, rolled up, and secured out of the way.
4) Connect the live and neutral wires to the proper sides of the G13 sockets at the live end. Make sure all wire connections are wire-nutted and wrapped with electrical tape, and make sure the fixture is properly grounded before reassembling it.
5) Install your new LED tubes in the fixture and reconnect power.