We, (or more accurately, my friend who has multiple 123s), bought a spring compressor. It cost less than $100 even here in Canada. You may even be able to borrow one or get a used one.

The opening in the engine bay had been opened up on my car, but doing that should not be a show stopper. It's possible some compressors may now be of a size that doesn't need that? I am sure you would get many comments here if you asked about spring compressors. Better than that tree option

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5