I've done both fronts and the rears on several 124s. Never used compressor on rear, but keep in mind the rears will come more or less straight down. The fronts can obviously turn more and I think it would be much harder to get them to come straight down in a controlled manner.

So yes it can be done, but I would not do it without a proper compressor and I would not tell anyone to try to do the fronts without compressors. I think it's to dangerous to do without compressor.

I think it would be nearly impossible to get the spring back in without a compressor. Although, someone will probably chime in and say they have done it.