What do i need to do to change my strut bushings on my 01 mustang?

in the engine --spinning main bearing shell
in the body , strut upper bearing rubber failure , sway bar bushes , suspension bushes
bad exhaust system-- rubber hangers

if you only replace one side,you will not be able to correct tow,do both sides,upper and lower and tie rod ends and all bushings,ebay has kits

If driving an older car I would replace all bushings. If they look worn and cracked yes. I have a 2002 Mustang I just bought and that's what I'm going to do. Do it now while the car is getting the struts done, Instead of down the road and you have stability trouble. But if you can't do it yourself I can see why you ask. Money. Maybe some auto repair shop is telling you so. Get a second opinion.

Sway bar and suspension bushings - Yes, Shock/struts yes if shocks/struts haven't been replaced already. Check stabilizer links before changing anything, Stab links wear out and are common to make rattling noises.

Here are the instruction on how to replace your control arm bushing. please not that there is a special tool needed that you will need to get from you auto parts retailer. you can usually rent these tools.

1. 1. Turn the control arm over in the arbor press, then position the arm so that it is supported by the receiver tool MB-990799 as shown.
2. Position the new bushing into the control arm so it is square with the bushing hole. Position the installer tool MB-6644-1 or equivalent on top of the bushing, with the bushing setting in the recessed area of the installer tool. Press the bushing into the control arm.
   
3. Press the control arm bushing into the control arm until the installer tool squarely bottoms against the surface of the control arm. When the installer tool squarely bottoms on the control arm, the bushing is installed in the arm in the correct position.
   
4. Install the tension strut into the strut bushing in the control arm. Position the tension strut in the control arm with the word FRONT stamped in the tension strut positioned away from the control arm. With an open end wrench on the flat of the tension strut to stop the tension strut from turning. Tighten the NEW tension strut-to-control arm retaining nut to 110 ft. lbs. (150 Nm).
   
5. Install the lower control arm and tension strut back onto the vehicle. Refer to the Lower Control Arm procedure earlier in this section.
   

Control Arm-to-Tension Strut Bushing
To replace the control arm tension strut bushing, the control arm and tension strut assembly must be removed. The removal of the bushing requires the use of an arbor press.

1. Thoroughly lubricate the replacement tension strut bushing, control arm and installer tool 6644-3 or equivalent with a silicone lubricant.
   
2. By hand, install the tension strut bushing into the large end of the installer tool. Press the bushing into the installer tool as far as it will go by hand.
   
3. Position the control arm in the arbor press so that the tension strut hole in the control arm is centered on the receiver tool MB-990799 or equivalent. Position the installer tool with the previously installed bushing, inside of the tension strut bushing hole in the control arm. Position the installer tool on top of the tension strut bushing. Using the arbor press, press the tension strut bushing into the control arm. As the bushing is being pressed into the arm, a pop will be heard. When the pop is heard, the installer tool will slightly move up off the control arm. At this time remove the control arm assembly from the press and pull the tool MB-6644-3 off of the tension strut bushing in the control arm.
   

There are several possible causes to your problem.

Most likely it is a ball joint.
A bad strut mount will make a similar noise. Sometimes dirt/rust in-between the strut spring and the rubber insulators can cause a creak.
If the environment is really dry or the rubber bushings on the car are really old, they can cause a creaking noise.

I would have it checked out because if it is a ball joint, it will eventually cause uneven tire wear and can even separate, resulting in total loss of control of the vehicle.

I belive you talking about strut tower bushing.
Yes you can replace it without repl. strut , but you have to take strut apart. Very common on Toyota's.
You need a strut compressor for this job.

Check all bushings in the control arms and springs for wear.

Well there are stabilizer bar bushings, control arm bushings and strut mount bushings. The stabilizer bushings are usally bolted around the the stabilizer bar and attach to the frame. The control arm bushings are usally pressed into the control arms. The strut mount bushings are on top of the struts. Normally they are replaced as needed. The strut mount bushings are good to do when replacing the struts.

Shocks/struts need to be replaced.