You should be able to. You will need to make sure to remove the four nuts that mount the turbo to the exhaust mount. BTW, two of the nuts will be larger then the top two nuts. It doesnt take too long actually. Its just that one pedistal mount nut on the rear drivers side thats a PIA!

Four O-Rings sound about right. Two of them will be for the oil passage from the block to the turbo pedistal. The others should be for the plunger on the turbo.