Nasty neighbor placed a lien on our house 4 years ago claiming we delayed his construction not permitting him to drive over a strip of land we own.

Unless California law is very differeent from where I practice, you can't simply "place a lien" on someone's house.  You either need a contract that allows you to do so (e.g. a mortgage), have provided certain materials or services to improve the house (e.g. a contractor who performs work on the house), have a claim to ownerhsip of the house that you litigate (e.g. you sue claiming that the owner breached a contract to sell the house to you, in which case you have to start your suit within a certain period of time or the lien is invalid) or obtain a judgment against the homeowner in a lawsuit, which allows you to place a judgment lien on the house untill the judgment is satisfied.  Of couse I don't know the whole story, but of these the only one that sounds plausible is that your neighbor sued you and obtained a judgment against you.  You can't get rid of the lien unless you either pay the judgment, or gat the judgment vacated by a court, and almost the only way you can do that is if you were not properly served with the suit and a default judgment was entered against you.  You need to investigate exactly what type of "lien" your neighbor has against your house to see on what it is based and if it's valid.  You may want to engage a local attorney.