You want the lower control arm to rotate so like Cab said back out the adjusters all the way but don't remove the bolts, leave them threaded in the arm.

Make sure the shock is disconnected and the pivot nut is loose.

Make sure the Lower Ball joint, Upper Ball joint OR Upper control arms pivots are disconnected. Any of the three will work to give you the ability to rotate the Lower arm enough to get the T-bar in.

If you have the brakes and spindle connected to the LCA it helps to have a jack under the LCA to support the weight.

I grease both sockets and the ends of the bar. More for corrosion protection than lubrication. IIRC the service manual says to.

Insert the Tbar into position with the rear hex sticking out of the rear of the transmission crossmember. I usually have the LCA completely loose and slip the LCA on the front of the Tbar then slide them into the K-Frame as an assembly but since your LCA is still holding the brakes and spindle slide the Tbar in from the back (Transmission Crossmember) may be the best option.

Rotate the LCA by hand or jack until you can slide the T-bar into the LCA and the transmission crossmember. I will often use a rubber mallet to coax it in at the back.

Once it is engaged on both ends I use a mallet and wood dowel (don't want to scratch or ding the bar) to drive the bar in at the back.
Old Broom handles work great. Once you can get the clip in the socket you are done.

Jack up he LCA, connect the Ball joint & Shock.

Set the ride height and then while the suspension is still on the ground tighten the LCA pivot.

Hope it helps