Those instructions do say "Never eat uncooked sausage"
I like to course grind up about 10lbs well trimmed scrap deer meat and the same with 1-2lbs of beef fat, then medium grind/blend together.
The summer sausage mix gets mixed in with it, as your instructions indicate, then placed in refrigerator overnight (12-24hrs).
The next day I'll tightly stuff meat into 2" diameter casing, then take stuffed casing and hang in smoker....your choice of wood chips (I like Hickory)........and let sausages slow cook over several hours as Double S mentioned.
I bought an inexpensive Little Chief electric smoker probably close to 20 years ago and it's worked fine for my little once a year summer sausage smoking.
Empty/refill the wood pan w/fresh chips each hour a couple times, then just let it cook.
Since it can be cold out when I do this, I did end up getting an insulated cover for it to help keep cooking temp up. After they have cooked for a few hours, I stick the probe of my electric meat thermometer in middle one of the sausage sticks and if not done, continue to let it slow cook until meat hits 140 degrees.
2009 Martin Bengal M2 Pro Cam w/factory STS & CCS.....66lbs, 29" DL, 422gr @ 272fps, Winners Choice string/cable, Trophy Taker drop-away Rest, Scott Release
1996 Martin Firecat XRG Pro Series w/Ultra Sonic wheels.....69lbs, 29" DL, 465gr @ 245fps, w/fingers & Martin leather glove