Holy cow! That doesn't even look like Abelia! The best time to do major pruning will be next March when you can take the plants down by up to half. For right now it would be okay to prune them back by a quarter. You can even use electric shears if you want to. Abelias are pretty hard to kill and recover quickly from shearing. If you want a more natural look you could remove individual stems manually but it would take a while.
That is awesome! I copied a page from a library book "The Pruner's Bible" and for remedial pruning, if an Abelia has gotten out of hand, in spring cut stems to 6-8 inches above the ground and in summer remove up to 1/3 of the weakest and thinnest shoots to prevent overcrowding. But you probably don't want to do that, so I think plantfreak has made a good suggestion.
It also says the best time to prune most Abelia's is in early and late spring.
I took a CHAIN saw to an Abelia and an out of hand Wieglia(sp) and they laughed at me and took off from the bases like no tommorrow and I didn't miss a bloom.
I hacked them late winter so I'm very surprised the pruners bible says in early and late spring. It's the pruner's bible so they must know. Do not be afraid of your loppers!!!!!! Loppers and saws are your friends. Smile.
The "best" time to prune doesn't necessarily mean it's the only time you can successfully prune something. Plus late winter and early spring really aren't all that far apart from each other, so if early spring is one of the best times to prune, it's not surprising that late winter would have worked fine as well (the caveat with pruning too early is it could stimulate tender new growth that could then get zapped by frost, that's probably why spring is the recommended time rather than late winter).