Elaborations
To read about how to use conventional software (SPSS, SAS, or Amos) to estimate the SRM click here. One can also download a paper that discusses such and had SPSS and SAS syntax at https://davidakenny.net/papers/dyadmlm/downloads.htm.
On page 210, it is discussed how relationship effect estimates can be used to estimate API and other dyadic models. One can use the raw data to estimate dyadic models with relationship effects as described in this paper that can be downloaded.