I found 3 different big files taht references to SP5 but I am confuse about
what of these are the one that I need,

11 Jan 2006 nw65prodsp5.iso 634444K OES NetWare Prod SP2 \ NW6.5 Prod SP5
11 Jan 2006 nw65ossp5.iso 510432K OES NetWare OS SP2 \ NW6.5 OS SP5
Overlay CD
10 Jan 2006 nw65sp5.exe 771476K OES Support Pack 2, NW6.5 Support
Pack 5

Also I would like to knew about how will be the safest way to apply it.

Hope you can help me