A energy link is one of the more so frustrating things to cut earlier on especially if its foreign, your own just requires you to dissolve it at will, but foreign ones require a lot more and can become really irritating after a point.
So first off the thing you need to understand is that chances are the person/entity/etc that is creating the link is consciously creating it, so the first thing is you have to learn that you will be fighting against a conscious thing to cut the link normally, unless it is a construct.
Okay the first step to cutting a link requires you to learn the exact position of the link in the first place, else it is kind of pointless to actually try and cut it. Find the location through energetic sensations and or your senses, once you pinpoint the location move on.
Now that you have the location, I want you to begin to cover that area with energy and delve to see how deep the link goes into your energetic body, sometimes it may have drilled in and latched itself, if it has, then the first step is to pull it out.
Begin to pull it out and or coax the link out, you could technically ignore this part but its better to do this, if that is too slow you technically can cut a section of your energetic system out and then regrow it later to make it go faster.
Now that you have the link out, you should be attempting to either one... Cut it, and by this I mean either with a energetic construct or through simply willing it to slowly "Break apart" from the target, this isn't a literal cut like most people think, rather, a cut as in a connection between two different points.
The other method is to redirect the link back at the sender in a loop style fashion.