ACP17,
Hi, as John says, it IS easy.....however the first time a dipped bulb failed when my 1.7 was 5 years old, I had a hell of a to get the unit off the car body! There was something that just stopped me wiggling it free - a restraint device! Well that and presumably 5 years worth of road dirt getting at it, to stiffen it up.
There is a little slot on the underside of the headlight unit that slides over a disc sitting up from the bottom of the body recess, then the quarter turn "Open / Close" control (behind one of the headlight units retaining screws) slides a bar across the front of that underside slot, to either physically restrain, or else unlock it! The restraint disc is something like - well think of an 8" or 10" round head nail that's been knocked into a piece of would, leaving 1/2" or so sticking out.
Sorry, I haven't got a photo of that, but I do of the underside of the headlight unit, so you know what your up against! See the very badly drawn red circle around the restraint slot! Once you know what's actually holding it, it is easy to wiggle the unit free off it in a couple of minutes and it gets quicker every time you need to do it.
When re-installing the unit, don't forget to reattach the drain hose, so you don't get loads of condensation inside! Oh, you mentioned replacing the indicators with LED's, I hope you do the side lights with bright white LED's as well, as they're behind a diffusing lens. I did that after I discovered both +50% brighter dipped bulbs had each blown over two days, before I'd even noticed the first one had! That became apparent when I pulled onto my garden at night and realised I'd driven down an unlit motorway with only two sidelights that only seemed to muster "one Birthday cake candle power" between them! Those sidelight LED's never gave any problems at many MOT times and I certainly felt safer if a dipped bulb was ever to blow while I was out and about.
The reason I go into detail about the restraint device is - look what a (professional) garage did to my headlight unit! They snapped off 3 of the 4 plastic clips holding the clear polycarbonate outside to the main body of the unit. I noticed that quite sometime after I had the failed aircon condensor replaced and had to reattach the headlamp outer to the main body with the aid of thin green garden wire, pliers and bit of problem solving thought!
Over the years that stuff ended up holding together lots of the car!