Lifters and lash adjusters are the same thing. Yes you need to remove the camshaft. After you remove the camshaft be sure to lay out the followers in the order of which cylinder they go in. With the camshaft out of the heads you can pull the lifters out to replace them. You need a special valve spring compressor tool http://cgi.ebay.com/ebaymotors/18051...fvi%3D1&_rdc=1
when you compress the valve springs you have to watch that the whole valve and everything compresses, if you compress just the spring and the keepers fall out the valve can fall down into the cylinder and you'll be royally screwed. just be careful, it's not that difficult. Also make sure you torque down the cam with a good torque wrench, I believe the 3 valves are like the 2 valves where there are no cam bearings, they ride right on the journal and oil is all that keeps it from wearing.
'97 F-150 4.6L 5-speed Off-road: PI head swap, 3.8L Taurus E-fan w/DCC controller, VMP Tuning custom tunes with SCT X3, Pacesetter shorties, Gotts mod, 3" body lift, 285/70/17 Nitto Crossteks, Expedition front brake swap, Herculiner two-tone, 2-6" driving lights behind billet grille, 2-10" subs under rear seat.