Welcome to the addiction! Modifying your bike can become quite addictive, and there are lots of good resources for doing things to your bike. Shadowriders.net is another good source for information on mods, including photos and writeups on "how-tos", though their "forum" seems less "active" than here.
Is yours the chain or shaft drive? If it's chain, you might consider changing to a smaller sprocket for better highway RPMs and less feeling like you need a 6th gear.
Thank you all, my bike is a chain driven one, just saving some money to buy tools and parts for the sprocket mod. Been looking at customizing my stock bike and it is addicting haha.
A Spirit 750 DC you say. Nice Bike. But then Im kind or bias as I bought mine new in 2001 and Im still riding it going on 17 years now. and I love it. Best of luck with yours and again Welcome to the forum.