It depends on how you installed it.
I suppose you installed it from the source by doing configure && make && make install. If so, I would suggest assembling and installing it again, now in a special directory. Then, given this list of installed files, delete it manually.
So something like this:
ERLTMPDIR=/tmp/myerlang
./configure && make && make DESTDIR=$ERLTMPDIR install
files=`find $ERLTMPDIR -type f`
dirs=`find $ERLTMPDIR -type d`
Given that the list of installed files and dirs, you can carefully remove all the files that were installed on your system.
:
real_files=`find $ERLTMPDIR -type f | sed 's#$ERLTMPDIR#/usr/local#'`
( /usr/local - , erlang)
, , erlang init.d.