HCU 4WABS brake bleeding process

[minnnplates]

1st time replacing hard brake lines. I've been reading that if you allow air to enter from upstream, you'll have to use a special tool to cycle the solenoids in the HCU. I simply want to replace the lines from the master to HCU along with all 4 wheels, avoiding any complications of special tools. If you've done this before, are there any thechniques to keep the process simple? I'm having a difficult time undserstanding since the manuals simply state not to get air into the HCU.