It can take a few days, but with the right tools and some help, you can easily take out your old bathtub and install a new one. It is going to take some time to learn how to install a bathtub replacement but there are plenty of articles available as well as videos online.
You can also get help from your local home improvement center. Generally, you will need to start by taking out the old tub and replacing it with the new one. This part of the job can be tricky if the tub is between two walls and is not a freestanding tub.
This job requires turning off the main water. Then remove the faucet and knobs from the bathtub. Remove any drywall necessary above the tub on both ends. Watch for any electrical wiring or plumbing.
Cut away any silicone and remove the flange screws. Get help lifting the bathtub up and out. Putting the new bathtub in is as easy as taking the old one out, and is actually usually easier as long as the drain and knob holes are in alignment with the old tub’s.
Put the tub in and repeat the removal steps with the flange in reverse. Make sure it goes over the p-trap correctly. If you need to, use ledger board if needed. This is where you might need help again.
When you get the tub down, check it with a level. Don’t place the level on the bottom of the tub as most tubs have an angled shape that allows for better draining. Test the level by putting it on top of the tub.
More details can be found in online tutorial videos. You can also learn how to install a bathtub from your home improvement’s bath and plumbing department.