It takes a bit of technique, but it is pretty straight forwards changing them without taking the bumper off.
U need to use the tips of your fingers mostly to guide stuff about, you don't really need to get your whole hand in there.
Try and get the back cover off the headlamp,
With your tips of fingers try and prise the headlamp wiring off the bulb
next unclip the bulb retaining spring (u can do it via feel)
Slip the bulb out, making sure not to drop it! Take note of the position of the bulb
Get new bulb (dont touch the glass!) get it in the same position as the old one (bulbs have a up/down)
tips of your fingers, guide bulb back into headlamp.
Get it to sit square.
Clip back the retaining spring (this can be a bit of a faff!)
Pop the wiring back on
REfit back cover.
Should take no more than 5mins each light!!