Probably a numpty question which is probably why I can’t find any info but want to make sure I don’t get caught out by something unknown.

The plastic t piece is weeping so I have a new top hose assembly, am I able to replace this without dropping the coolant and can I just follow what I would say is the usual procedure:

Make sure your heating is set to hot.
Run the engine check it's blowing hot air.
Leave it in that position and switch off let it cool down
Replace the assembly.

Click image to enlarge

Click image to enlarge

I never dropped the coolant when I replaced mine, just undid the clips and replaced the new part. Topped up the coolant and got vehicle up temp whilst bleeding from the air screw. 2011 TDV8 Vogue SE

I did exactly as above when I did mine too. I also put a little jubilee clip on the new pipe….. still no idea if that was the right thing to do or not….

 2011 Range Rover Vogue SE 4.4 TDV8

Previous cars :
2003 Range Rover Vogue TD6
1999 Discovery Td5 ES
1995 BMW M5 3.8 6 speed
1992 Range Rover 3.9 Efi Vogue
1992 BMW M5 3.8
1988 BMW 735i SE
1989 Ford Sierra XR4x4 2.9i
1981 Ford Fiesta Supersport