Roots very easily.

Google rejuvenation pruning and sharpen those loppers.

But as Babs said it is ill suited to that spot and will never work there. I'd start three or four ground layers for a better location and dig this one out when the weather lightens up. It will be dicey to not disturb those steps- I'd likely take those up first. OR I would cut it right to the ground and cover the spot with thick black plastic for a couple of years. If you were diligent about killing any sprouts immediately you could kill it that way.

An old forsythia can be a bear to move- here is one of seven my husband dug out when we bought this property.

cutting it completely down.. with no insult to the huge root mass ... and in 2 or 3 years ... you will probably have the same plant there ... unless you want to do heavy pruning every year ...

if not.. get rid of it ... as noted .... the easy way.. would be to cut it to the ground and apply a stump killer ...

see link

im not much impressed by your master gardener ... but what a great friend ... to go all jungle whacking on it .... mull that.. lol ...

ken

its the same idea.. regardless of the flowering shrub and though the concept is a 3 year rotation ... i would just go full bore ... and skip next years bloom .... and then in 3 years.. start the cycle ....

https://duckduckgo.com/?q=rejuvenation+pruning&t=ffcm&iax=1&ia=videos

Thanks for all your thoughts. All really helpful ideas. It didn't flower this year like it did last year when it was covered in yellow blooms. Does this fit into the idea that it won't bloom again next year for the second year due to the pruning of damaged parts?

We untangled the branches which grew so twisted but may have helped support the branches. My friend said with all the rubbing, it would have cut into the bark and made the shrub susceptible to disease. As we untangled, they literally flopped over and some branches busted. We only pruned down what broke as a result. I know it looks pretty terrible but it's not her fault. That's why I'm here asking about the next step. I wouldn't want her to feel bad for trying to help.

What looks like steps are a retaining wall. Can I ask what makes this a particularly bad spot? The shrub is on a hill so I wonder if maybe that prevented it from getting good water? What accounts for the droopiness?

Even with as bad as it looks now, it provides some privacy for the sidewalk that runs in front. Is fall then the best time to make any drastic changes?

Thanks again!

If it was me and I wanted to keep it, next spring the day it finishes blooming (if it even does) I would remove all the largest limbs down to the ground. I might even do it this fall and not even try for 2018 blooms.

Then after it leafs out in the spring I would sit down next to it and very meticulously and thoroughly decide how large I wanted it to be and remove all the small stuff that doesn't suit that vision. I would probably try to leave the parts farthest from the wall and remove what is closest in the interests of roots never damaging it. Then I would keep up with it and keep the size manageable.

"The shrub is on a hill so I wonder if maybe that prevented it from getting good water? What accounts for the droopiness?"

It'd droopy because you removed foliage and what is left had insufficient sun behind what you removed and grew stretching for light. It is droopy because, as you stated, it was overgrown and neglected.

The water is easy- make a dam out of a strip of plastic and half bury it on the low side. This holds water long enough for it to penetrate the soil. Like so (bonus improvised shade demo)- I use pound in edging for small things and plastic landscape border for large things. It is essential for gardening on a hill, especially when establishing things. I generally remove them after a year or so.