I've replaced four strut inserts on 900 series bricks. First strut (six hours). Second (three hours). Second car (two-three hours, both struts). Just plan on taking your time. I can't fathom for the life of me why that first car was so difficult... One trick I remember using when feeding the strut insert (threaded shaft on top) up through the 'shock tower', is that I used a long 1/4" extension taped to deepwelled socket. This helped me guide the strut, which is trying to expand with all it's might, up through the mounting hole.

I still can't believe it took me so long (I feel I'm pretty competent...slow I guess, but able!). Just make sure you give yourself two days to do the job. And DON'T forget to grease the strut inserts.