How do I get rid of my house?

[Lindal Kidd]

if the center of the object is across the border on your neighbor's land, have him Return it to you

[Lindal Kidd]

if the center of the object is across the border on your neighbor's land, have him Return it to you

[Peewee Musytari]

If there is no delete option, are they your prims?

Right-click and go to edit and look on the general tab at who the owner is.

[PeterCanessa Oh]

In-world your neighbour may well be able to help if they are more experienced.  :-) Since they're complaining and you're doing your best it pays to help each other