its no biggie really.
ive done my own on a JTD many time without issue, other than getting the right replacement filter that is!
so long as all off, there will only be minimal diesel loss/spill, and only for a moment or two.
i find it easiest to undoe the bracket from the firewall with the two nuts, and swing it up toward you to undoe the filter from the housing and the water sensor if you have one.
toughest thing is finding a filter with the right length, and the right thread for the water sensor, unless of course, you order a genuine one which is only a few quid more than a quality aftermarket one, but the Mahle filters are pretty good i find.
all threads are typical, no opposite or left handed threads, and other than an over tightened filter you shouldn't struggle with anything, and just like an oil filter they should only be strong hand tight, altghough i normally give them a tiny extra nip with a tool if handy.
good luck, its no biggie...