Save n3.lexer.lua somewhere - it's a Lua script to tokenise Notation 3, Turtle,
N-Triples and SPARQL.
The SciTE.properties file includes various settings for dealing with N3 files.
You can either save it as-is in the directory where your N3 files live, or rename
it to ".SciTEUser.properties" and place it in your home directory. If you've
already got a properties file, just append these properties to the end of it.
You will probably want to change the path to the lexer extension to reflect
wherever you saved n3.lexer.lua.
Lastly, the patch scite211-replaceselection.patch is a patch for SciTE itself,
porting the SciTE-for-Windows "replaceselection" feature to SciTE-for-Unix.
It should work in SciTE 2.11 and 2.12 and perhaps earlier versions. As
of 2.13, it should be included in the mainstream version of SciTE so is
no longer needed. Installing this patch is optional, but it will provide
you with a handy way of adding @prefix declarations to Turtle files.