I've separated out electricity but not water (never heard of sewer being separated) and I've always had separate gas meters on my properties but have separated the heating system on one. You would contact an electrician plus the power company to separate electricity. Water you could have a plumber do it or do it yourself if you do the sub-meter route. I would have a plumber do the gas if you have that in your area.
The heating system, while straightforward, wasn't cheap for my 3 unit and will have a longer payback period. I don't remember exactly but it was around $10k total for labor and the 2 new boilers. I got a deal on labor as I know the contractor personally and helped out a bit with the project. Worth it still as now I don't have gas bills to contend with for heat which I would say was around $1k a year. I know that is a long pay back period but don't plan on selling anytime soon, plus you never know what nat gas prices will do. I believe it'll help with eventual resale of the property as well. The water heaters were already separated.
It cost me $8500 in my HCOL to get the electric separated on a 3 unit. This was labor and parts and I know the electrician personally so it would have cost more going through someone else. For that I also had to deal with the power company. The electrician got the 4 gang meter pan installed and went through all the fuses and whatnot to divvy out and installed separate panels for each unit. The power company supplied and installed the new meters (at no charge, at least not yet) and verified all the work around the 4 gang meter pan was done up to their standards. I also had to get it approved by the city which was pretty easy.
This was a no-brainer and has a payback of about 3 or so years (probably less with how my tenants use the AC in the summer) plus again, it'll help sell the property down the road.
I really wanted to separate the water as I found a few good sub-meter companies but the water lines go every which way and make it impossible to attach a meter to one. In theory I could attach one to each water heater since they are separated out, but I'm not sure if it's worth the hassle.