1. Put multihome in your path
2. Depending on your shell, put the following at the top of its initialization
file.

CSH (.cshrc):

if ( -f ~/bin/multihome ) then
	# Destroy environment
	env -i
	# Resassign HOME
	eval `~/bin/multihome`
	if ( -d $HOME ) then
		cd $HOME
	endif
	source ~/.cshrc
endif


BASH (.bash_profile):

if [ -f ~/bin/multihome ]; then
	# Destroy environment
	env -i
	# Resassign HOME
	eval `~/bin/multihome`
	if [ -d "$HOME" ]; then
		cd $HOME
	fi
	source ~/.bash_profile
fi