to remove the arm just pull/pry towards the clutches, its just ball joint type fitting, it will just pop off and no you do not have to remove the oil tank, once you have the front piece of the airbox out ( 1 screw in the very nose of the sled) then just grad the remaining peice of the airbox from the front and pull, (the warmer it is the more flexable and easier it is to get out), after that there is enough room to get the throttle bodies out, but remember there will be 2 coolant lines attached to the bottom of them,(unless they have been bypassed, depending on who put your sled togther) make sure to disconnect them, hope this helps.