You dont say exactly which version you have, but you will also need to refer to the upgrade matrix to confirm if you need to do a multi step upgrade approach.
From the compatibility chart, this is the upgrade path for NPM:
Network Performance Monitor (NPM)
Orion NPM 7.8.5 ⇒ 8.5.1 ⇒ 9.1 ⇒ 9.5.1 ⇒ 10.1.3 ⇒ 10.3 ⇒ 10.7
So if you ar on a version between 9.1 and 9.5.1 then the first install would be the 9.5.1 then 10.1.3 etc
You may have to request the older versions are added to your Solarwinds portal.
As you are upgrading from a pre 10.0 version it would also be a good idea to check the resource requirements which are on page 41 of the NPM admin guide
You have some very nice features to look forward to