SD
I am sure an instructor will quote the relevant JAR paras, but as I understand it the training will be agreed in each particular case and therefore will be a matter for discussion with the flying school offering the conversion (and certifying it.)
Moving from a 152 to an Arrow is not an enromous leap, but there are enough tricky systems such as gear/alternate gear extension, fuel management (boost pump and L/R tank selection), CS prop etc. to make it wsie to invest in a sensible amount of training.
Also the 152 will cruise at 85-90kts, whereas the Arrow will be about 35kts quicker, so its good to have some backup whilst getting used to covering the ground at a more rapid pace.