I believe I may need a new transmission

With the tools you have, it should not be a problem replacing the transmission but before you start on it, I would suggest performing some diagnostic testing first, just to confirm that the transmission is faulty.

Which engine and transmission do you have?

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Refer to diagram for identification.
Let me know the code so I can get the necessary information for you.

ALL GEARS INOPERATIVE

Check oil level and pressure, drive link, manual linkage, input shaft, reaction carrier, differential and torque converter.

This condition may also be caused by the thermal element moving forward, because a retaining clip has fallen out. The clip may be located in the bottom oil pan.

Here are the procedures.

3T40 TRANSAXLE
Removal
1. Disconnect and shield negative battery cable. Remove air cleaner. Remove bolt securing transaxle throttle valve cable to transaxle. Remove shift cable and bracket from transaxle. Disconnect electrical connectors as necessary.

2. Disconnect oil cooler lines from transaxle. Plug ends of lines. Remove all transaxle-to-engine bolts except bolt nearest starter motor (leave this bolt loosely installed). Support engine from top. Raise and support vehicle on hoist. Remove left front wheel. Remove left engine splash shield. Remove pinch bolt from ball left ball joint. Disconnect ball joint from left control arm. If steering intermediate shaft is not disconnected from steering gear stub shaft as described in next step, these components could be damaged, possibly resulting in loss of steering
control.

3. Remove pinch bolt securing steering intermediate shaft to steering gear stub shaft. Remove stabilizer bar. Center-punch the 2 spot welds securing left crossmember to rear crossmember. Left crossmember is the 90-degree frame piece that acts as the left frame and front crossmember. See Fig. 1. Drill out spot welds using 7/16" drill bit.

4. Remove bolt securing left end of steering rack to rear crossmember. Remove 4 bolts securing left crossmember to right frame. Using jack stand, support left crossmember from bottom. Remove 2 bolts securing left crossmember to body.

5. Remove 2 nuts securing left transaxle mount to left crossmember. Remove left crossmember and jack stand. Remove starter and torque converter shields. Remove 3 flexplate-to-converter bolts. Remove 2 transaxle extension bolts from engine-to-transaxle bracket.

6. Remove rear transaxle mount bracket assembly (it may be necessary to raise transaxle). Using transaxle jack, support transaxle from bottom. Remove 2 braces from right end of transaxle. Remove left drive axle.

7. Remove remaining transaxle-to-engine bolt near starter. Remove transaxle and right drive axle as an assembly.

Sorry I missed out this.

Stands should be sufficient but ensure it has sufficient height for the transmission to come out from under vehicle.

We as professionals too have to do with stands at times when hoist are filled up.