Comment a line with SED

I have around 25 hosts and each hosts has 4 instance of jboss and 4 different ip attached to it . I need to make some changes to the startup scripts. Any tips appreciated. I have total of 100 instances which bind to 100 different ip address based on instance name.

For example
File1

START="/usr/local/jboss/bin/run.start -c instance1 -b 10.120.1.1"
STOP="/usr/local/jboss/bin/run.stop -c instance1"

File2

START="/usr/local/jboss/bin/spcrun.start -c instance2 -b 10.120.1.2"
STOP="/usr/local/jboss/bin/spcrun.stop -c instance2"

I need to change it to the following.Changes are addition of ip to second line,change in path and command

File1

START="/jboss/bin/run.sh -c instance1 -b 10.120.1.1"
STOP="/jboss/bin/run.sh -c instance1" -b 10.120.1.1
file=File1
. "$file"
ip=${START##* }
{
printf 'START="%s"\n' "${START#/usr/local}"
printf 'STOP="%s %s"\n' "${STOP#/usr/local}" "$ip"
} > "$file"