One approach is to love something higher, such as Arne Naess' ecological self: "The ecological self is that with which one relates."
Most of the effective arguments I have seen regarding loving in the face of evil rely on one of two assumptions (or both):
- There is a little good in everything
- You cannot be 100% proof positive that something is pure evil.
If you disagree with both assumptions, it may be hard to develop an argument for loving in the face of evil. However, either assumption gives you an "out."
If there is a little good in everything, you can strive to love a "higher power" defined to be all of you plus the good within the evil. You then support/love that. The end result is you loving a little piece of the "evil" which is actually good. This supports what the evil is trying to do, but can subvert their efforts (in theory)
If you are not 100% proof positive that your declaration of evil is right, then you can strive to love a "higher power" defined to be everything good, plus this particular evil. The end result may result in evil prevailing, but it also prevents the false-positive where you destroy something good because you misinterpreted it as evil.
As for ways to implement this... that's the topic of hundreds of philosophers striving for peace. I certainly won't be able to enumerate them all here. They also depend on what you believe you should protect from this evil. If you need to protect your entire body from it, that could be difficult. If you only need to protect the tiny spark from which you will rebuild, its easier. The approaches diverge from there.
Also worth noting is the Chinese philosophies. Due to the nature of yin and yang, they have a very different approach to good and evil which supports a different set of solutions to this problem. I do not, however, consider them a direct answer to your question because their approach is really an alternative to loving those who do evil which works with their philosophy.