Using the bigshot or hand throw (if you're good and strong!! and no power lines about!!!) get the throw line over and through the centre of the head pull back one line with a pulley and your climbing line fed through the pulley...your line has to be long enough to reach the ground doubled (if your using a dynamic climing system) pull the 1st line back till the pulley is set above the dead fronds visible to you on the ground and centred. The 1st line is then secured to either the trunk a porty or something bomb proof!
Climb up (after satisfying yourself the set up is stable and secure!
) on reaching the point above the dead fronds attach a false crotch around the stem of the palm...this is what you'll work off...lanyard into the head, and change your climbing system from the pulley on the 1st line to the false crotch...if you've thought ahead (anchor hitch or similar) you should be able to detatch the pulley and keep it on your saddle then the 1st line can be dropped safely from the palm. Because you are cleaning the palm you can either move the f/c down with you or with enough throw line retrieve from the ground at the end.
Yes i know sounds so easy, and yes i know its not! But that is the method I would employ to do such a nasty job....really I'd be wanting to fell the buggers, or work from an EWP...in reality I wouldn't get to do the job as Eric often points out very dangerous for very little pay!!