It's pretty simple: you define the target customer, create messaging to match their pain points, you do outreach via email and/or cold calling, schedule demos and close deals. Inbound marketing will play a role too, but that takes time you don't have.
Of course, the devil is in the details.
The target customer needs to be defined down to an individual level and you need to validate the specific pain point for that specific target customer. Moreover, depending on the impact of your product, you may need to create messaging for any potential influencers in the decision making process.
Once you've created the messaging you'll need to build a prospecting list. The easiest way of doing this is to use LinkedIN to create a narrow prospect list. Ideally you'll have a small group of around 50 target accounts to start, this way you can fine tune the outreach and messaging strategy for each account.
Assuming you've gotten your messaging right you can expect a 15-20% response rate of which maybe 50% will lead to a demo. In my experience, this is where most companies run into problems because they assume that demo = qualified lead and rush through this process.
The key is in the follow up because most of the sales process is going to happen without your involvement; prospects WILL seek out information from other sources and compare you against your competitors. This is where having a strong content strategy to reinforce the value of the product is crucial.
At a simplistic level, success is Saas sales is based on the volume of productive activity multiplied by your conversion rate at each stage. Setting up systems to measure activities is crucial for scalability.
Hope this helps.