NOISE AND VIBRATION WHILE DRYING

After reading everyone else's comments I started by pulling out the dryer, unplugging the power and exhaust. Next moved the dryer to an area where I had room to lay it on the back.
Then using a flat blade screw driver, I popped the top attached tape to the top so I could lean back the top without having to hold it. Removed the two screws from the front panel and removed the door safety shut off before removed the front panel. Then I layed the dryer on its back. Then reached under the drum, pushed the belt tensioner toward the motor puller to release the tension on the belt. Then slid the belt to the base. Pulled the drum up and out of the cabinet. Next I cleaned all the lint and crud out of the dryer components.
To remove the clips that hold the rollers in place, I use 2 small flat blade screw drivers. These are inserted at the back side of the horse show shaped clip between the shaft and the clip. When the two screw drivers are rotated like turning a screw they slide the clip out.
Next I used a socket wrench with a #8 metric socket(I didn't have the SAE size) and removed the screws holding the drum roller brackets.
I simply reversed the procedure to install the new rollers.
Since the dryer was on its back, when I put the drum back in, its own weight slipped it in place. Then pulled the belt around the drum and between the motor pulley and the belt tensioner. Holding the belt with one hand, I used the other hand to pushed the belt tensioner in and positioned the belt.
Then I stood the unit back upright and put the front cover on, replaced the door safety switch, removing the tape holding the lid and then cloed the lid. Of course I put the dryer back in place, leveled it, and it now runs like brand new.
My thanks to every one else who gave me hints that saved be about $450!