There's several options for what you're wanting to do.
The most common as mentioned above is type B. Removal of the existing ballast is required and rewiring to line voltage.
You can get these in single end and double end. I *believe with the double end option, it doesn't matter if your tombstones are shunted or unshunted. The double end allows for a hot side and neutral side whereas the single has to be hot on the same side. The other end pins are just for keeping the bulb in place. I'm not an electrician, but I've heard the double end is easiest to wire.
There's another option that uses a separate driver. This will give you the most light ouput and you can could dim the light, it's Type C.
Type A is a true homeowner DIYer. These are plug and play. Simply switch out your old flourescents and replace with new T5 LED and wallah! There are pros and cons of these.
Ballistic compatibility and ballast life among other things.
And, there's a type A+B.
Switch out the bulbs and when ballast goes bad, wire it up as a type B and keep using the new bulbs. Not sure how many you have, but this is an option if you have a lot of them and didn't want to rewire them all at once.