Cam bearing let down

Hey my FABO friends I need a little help. About six months or so ago my son and I took my 340 apart, intake, cam and heads well my back has been shot for years but with meds I was doing OK, and then bam it went out for good ( reason for the six months ) but I've had surgery since and today was the day to put it back together. I got a set of LA-X heads from IMM and a Lunati Voo Doo Hydraulic flat tappet cam, any way when I started cleaning everything up I noticed the cam bearings are shot, I've never changed cam bearings before, how hard will it be to do with the motor in the car, I have access to the proper tools. How I didn't notice them before, I don't know. Thank You very much for any help given.

Jeff