Replacing 1 rigid brake pipe abs block to front wheel

[robbocop33]

Doing a fair bit of work on an older Mercedes cls i bought(if you're thinking of taking off front wheel arch liners,DON'T,unless you're a welder!)anyway,i just want a straightforward step by step to replacing one rigid brake pipe from the abs block to the front wheel.
I have a good pressure bleeder but i just want to know what to do first before removing old rigid pipe at the block to avoid air in the abs block,i've heard jamming down the brake pedal partially with a stick jammed between the front seat and the pedal?it stops fluid loss while changing the pipes and hopefully stops air getting in,is that true?

[E-bmw]

Yes, it is true.

When you press down on the pedal the piston moves into the master cylinder bore & blocks off the fluid path from the reservoir to the pipes.

Ideally (obviously) do it with the bleed screw open to allow the pressure created by pushing the pedal somewhere to go.

[Smint]

Before you start undoing stuff does it have SBS pressurised braking system? if so read up carefully on putting the system to sleep for your own safety.

[robbocop33]

Pretty sure it doesn't,it's a 2006,but thanks for the heads up. ;-)