R users : how to uninstall a package installed with devtools::install_github("username/repo")

Question

installed a package in R using devtools, ie devtools::install_github("username/repo_name")

how do I uninstall this package?

user_4480248 · Answer

my question was incomplete, I had not completed installation. .

devtools::install_github("username/repo_name")
install.packages("repo_name")
#package is now usable 
remove.packages("repo_name")

leaving this here in the hope others find it usable.