digital phase lead algorithm
Do they lag 5 degrees for all frequencies? Or only for a specific signal frequency?

If you want to shift a signal by 5 degrees for all frequencies you need some kind of all-pass filter similar to a Hilbert filter. However the Hilbert Filter whether FIR or IIR shifts a signal by 90 degrees not 5.

However, if you want to add or subtract 5 degrees at a specific frequency, you need to this

delay = phase/( 2*pi * f). 

If your delay is an integer number of samples, you simply need to delay your leading signal by this number of samples. However, if the delay is fractionnal you need to delay the leading signal with a fractional-delay filter. 

http://users.spa.aalto.fi/vpv/publications/vesan_vaitos/ch3_pt1_fir.pdf