I've installed a couple and it takes a little patience, some strength, and a little intelligence. If you can afford to pay someone, it shortens the learning curve. Properly sized steel rods or pieces of rebar are essential to the tensioning sequence.Everyone I have seen get hurt trying to tension that spring was using two screwdrivers in those adjuster holes. NO shortcuts, that's how people get hurt. You need two, 20 inch long pieces of steel round stock. Mine have all been 1/2. If yours are bigger, you need rods to match the holes in the adjuster hub. Make sure you are on a stable ladder, you will be holding tension for a while. It is pretty straight forward if you keep your mind engaged and don't get in a hurry. Since the spring has a shaft through it, it is not going to get too far. Not as dangerous as a car spring.
It looks like you have a dual spring system. With that tag hanging in the way, I cannot tell. Be sure to unwind the other spring, controlling it with the rods, one hole at a time before you take anything apart. Be sure you are solid in the hub before you loosen the lock screw. You will feel the tension pressing against your hand. Count how many holes it takes to get the tension off, that is how many you will need when you wind it back up (1/4 th turn at a time) leave the adjustment hub loose while you are working on the other side.
When a spring breaks, the cable on the end often gets snagged up and damaged on the spool. Check both sides. Change everything that looks hurt before you start winding up the springs again.
It really isn't complicated, but it will hurt you if you don't pay attention.
I did this once, probably 10-15 years ago, on a neighbor's house. I don't remember where we got them, but we used those long pieces of round stock, too. They were great because they were long enough to simply rest against the door/ceiling to hold tension.Everyone I have seen get hurt trying to tension that spring was using two screwdrivers in those adjuster holes. NO shortcuts, that's how people get hurt. You need two, 20 inch long pieces of steel round stock. Mine have all been 1/2. If yours are bigger, you need rods to match the holes in the adjuster hub. Make sure you are on a stable ladder, you will be holding tension for a while. It is pretty straight forward if you keep your mind engaged and don't get in a hurry. Since the spring has a shaft through it, it is not going to get too far. Not as dangerous as a car spring.
It looks like you have a dual spring system. With that tag hanging in the way, I cannot tell. Be sure to unwind the other spring, controlling it with the rods, one hole at a time before you take anything apart. Be sure you are solid in the hub before you loosen the lock screw. You will feel the tension pressing against your hand. Count how many holes it takes to get the tension off, that is how many you will need when you wind it back up (1/4 th turn at a time) leave the adjustment hub loose while you are working on the other side.
When a spring breaks, the cable on the end often gets snagged up and damaged on the spool. Check both sides. Change everything that looks hurt before you start winding up the springs again.
It really isn't complicated, but it will hurt you if you don't pay attention.
I left the door open last night. Again.I see you took the rope off so you can't open the door with a coat hanger. I did the same.
I agree with others that it isn't technically or physically hard. However it is a job where you can't afford to take shortcuts. Invest in the proper diameter stereo rods (1/2 inch) and make sure they are FULLY seated before applying pressure. Keep everyone or of the "plane of death". Basically treat it as firearm safety rules. If you aren't 100% comfortable then hire it done.I have replaced a couple of these. Not too hard if you like fixing things. If you haven't done them before watch it on youtube; I believe you can do it.