It will depend on many variables. As a whole, let's start with Guerrilla Testing concept:
Participants are not recruited but are ‘approached’ by those persons
conducting the sessions. The sessions themselves are short, typically
between 15-30 minutes and are loosely structured around specific key
research objectives. The output is typically ‘qualitative’ so insight
is often rich and detailed.
Anyone on the service team can conduct ‘guerrilla testing’ on their
site or service but often the best scenario is for a researcher to run
the sessions with the designer or developer. The researcher can help
with defining the tasks, moderating the sessions as well as provide a
level of ‘objectivity’ by not being the person who designed or built
what is being evaluated. Involving the designer / developer in the
sessions enables them to see first hand ‘real’ people interacting with
their product, where there are areas for improvement and how they
might go about resolving any issues.
This approach also does away with any lengthy reporting back. Insights
can be observed, taken away and fed back into the design process
almost immediately. However, a brief summary with key findings and
recommendations can be written up as a more formal record. It is a
method that suits the ‘agile framework’ well.
Based on this , you can see the methodological procedure to follow is to grab a bunch of people and show them what you got in order to get qualitative answers.
However, as good as this methodology is, there are some caveats, being the main ones distraction, lack of focus and last but not least, possible inaccurate targets. In your particular situation, it is possible this last one might be your main issue since you'll probably need some degree of expertise from your participants.
With this in mind, my recommendation would be to get access to people loosely matching your target, which you can do by:
- Approaching people in colleges
- Asking for help on specialised forums
- Contacting peers and colleagues in your area or online (assuming remote testing is a suitable methodology for your purposes)
As an example, take a look to this Apple Watch Guerrilla Testing article which can give you some ideas on procedures as well as when and where to conduct this research