No real easy fix for this.
First off, you need a couple special tools to remove the cross shaft. One of them:
Plus a slide hammer.
From the FSM:
CAUTION: The differential bearings and the differential
adjusters must be reused in order to use this
procedure. If any of the items listed above require
replacement, this procedure cannot be used. Refer
to Differential Recondition section of this manual.
(1) Remove transaxle from vehicle. Refer to Transaxle
Removal and Installation procedure in this section.
(2) Remove long stub shaft from transaxle (Fig.
To replace the long stub shaft bearing, install stub
shaft in soft-jawed vise. Remove the stub shaft bearing
C-clip (Fig. 111). Install bearing splitter onto the
shaft. Install Special Tool # P-334 under the bearing.
Using a shop press, remove the bearing from the
stub shaft (Fig. 112).
To install the stub shaft bearing, position new
bearing onto the stub shaft. Install stub shaft into
shop press. Position Special Tool # 6558 above bearing.
Press bearing onto shaft (Fig. 113).
(3) Index the inner differential adjuster with a
cross hair as shown in (Fig. 114).
CAUTION: If short stub shaft has corrosion, use
caution when removing differential cover. Inspect
seal and shaft for damage after removal of cover.
Replace shaft and/or seal as required.
(4) Index outer adjuster (Fig. 115). Remove lock
bracket and back out adjuster exactly one revolution.
Then remove differential cover.
(5) Remove The inner adjuster lock bracket. Then
remove the inner adjuster.
CAUTION: Keep the inner adjuster for reinstallation.
(6) Lube inner adjuster threads with gear oil and
reinstall to the cross haired index marks.
(7) Install the differential carrier. Then install
stub shaft seal protector.
(8) Install the differential cover/outer adjuster
assembly with sealant applied. Install and tighten
differential cover bolts.
(9) Tighten the outer adjuster 3/4 of a turn. Seat
bearings by turning differential carrier three or four
turns in both directions. Finish tightening the
adjuster 1/4 turn to its index mark (original location).
(10) Reinstall long stub shaft, fill differential with
fluid and reinstall transaxle.
(11) After installing transaxle check transmission
side fluid level.
It does not seem possible with the trans in the vehicle. Looks like you need to adjust the shaft end play etc. I'm not entirely sure as I've never done this one myself. By the time you buy the tools to remove the shaft, and all the mess, just rebuild the transmission and be done.