Getting the tub to the bathroom
Hopefully you measured the overall width of the tub and all the doorways or passageways that you'll need to navigate in order to get your tub into place. However, sometimes corners can prove a difficult task to feat when navigating a walk-in tub through a hallway and into a bathroom door. You'll occasionally need to remove the entire door-frame in order to get the new walk-in tub into the bathroom. You may even want to consider enlarging the bathroom door upon replacing as there's no better time to do this.
Level the Tub
Once you've finally gotten you new walk-in tub in place, it's time to make sure that it's level. Grab a level and place it on top of the tub, be sure to check all four sides. There should be a minimum of four or sometimes even six feet on the bottom of your walk-in tub that can be adjusted up or down for leveling. Make sure to get the unit as level as possible at this stage because doing so later can be very difficult.
Connect the plumbing
Connect your plumbing to the tub and check for leaks prior to connecting your electrical system. If there are leaks within your plumbing, it's better to find them now, instead of having to work around wet wires. Fill your tub roughly halfway and check all connections for leaks. Note: It's also a good idea to have the tub filled to capacity before bringing it into the home to insure that you don't have any leaks around the jets which may be a manufacturer defect.
Connect the Electrical
Once you're sure that there are no leaks, go ahead and connect the electrical side. You'll want to turn the tub on and check for any malfunctions with motors while you still have the side covers off.
Seal Everything Up
After you've made sure that the tub doesn't have any leaks or other defects, it's time to put it all together. This means that you can go ahead and put the side panels on, put a short wall in front of the tub and ultimately caulk around every single seam. It's important that you don't leave any holes around the ledges, as walk-in tubs do have a tendency to spit water out the sides when the jets are active.