Could anybody help me to get a manual for the Sturmey Archer XRF5 ?

The SA site has the SRF-5 listed but doesn't give the manual. The braked hum manual is supplied. You might look at that as there will be a lot of commonality except for the brake parts. You'll need to take care though.

http://www.sturmey-archer.com/pdfs/Summit_XRD5_Brake_Hub_LTE_161.pdf