Installing Guix from source

[Reza Alizadeh Majd]

Hi Guix, 

I tried to build Guix from source on an existing version of GuixSD.  so I 
followed 
the instructions provided in official documents: 

https://guix.info/manual/en/html_node/Requirements.html
https://www.gnu.org/software/guix/manual/en/html_node/Building-from-Git.html

after build finished, I had two versions of Guix on my machine, the old one 
which
is located in store, and the new one  which is installed in `/usr/local/bin`. 

the problem is that the old instance of guix is detected as default on my 
machine. 
since I performed a series of  modifications on this new version, like changing 
the 
default channels and substitute servers, I need to replace old instance of Guix 
completely with this new one. 

Does anyone knows how can I perform this replacement? 


Best, 
Reza