Transmission jerks when downshifting

I just had the transmission pan gasket and filter changed due to a leak. Now when it downshifts to low around thirty mph, it jerks the vehicle. Took back and they said they relearned the transmission and it helped some. This van is old but transmission has worked fine until this! Still jerks when downshifts. Talked to a transmission shop, they say it most likely did not take the relearn, it will say it took, but when you drive it you can tell it did not which seems to be the case. They say it can take five to ten tries sometimes on older vehicles. Can I perform the relearn without special equipment? Thanks, Greg