You cannot install those bushings with a hammer. My first attempt I tried...and failed. It's definitely a press fit. The right tool is a bolt with the right size cup and washer to push/pull the bushings without damage.
The other option (which I used) is to remove the whole subframe and use a shop press. In my case, I bought a 12-ton unit from Harbor Freight for around $100. I replaced every bushing and all the arms.