I don't suppose the primers matter much, as long as you can amplify a length of DNA that gives an obvious change in fragment sizes, +/- the SNP, after digesting with the relevant enzyme (I don't know the recognition site altered by this SNP). All you need is the gene sequence to design them.

The traditional RFLP (Restriction fragment length polymorphism) method uses the restriction enzymes to digest a DNA source and use specific probes to hybridize specific fragments. It is kind of like Southern assay, and the resulting band patterns can be used for scoring. But, not sure what did you mean by primers involve in the protocol. Did you mean to produce a specific probe for the HER2 gene?

I see, you're referring to a probed RFLP. You can also visualise RFLP directly in an agarose gel - PCR a region that might contain your SNP and digest it with the enzyme for the restriction site that is gained or lost with the SNP. Much easier if there is only one specific SNP you are looking for. In this case you can use any primer pair that will give you a useable length of DNA

The technique of PCR a region, then digest and visualize the band patterns on a gel, should be referred to as Cleaved amplified polymorphic sequence or CAPS. It is like RFLP, and is an extension of RFLP. See http://en.wikipedia.org/wiki/Cleaved_amplified_polymorphic_sequence

I mean, what the sequence is the fw and rv primer so they can match with the specific part of the SNP of HER 2? am I should design it first?