Be careful though. You want to make sure that you get the appropriate recognition for your work. Unless something is done explicitly to counter it, the default is that unsexy work does not receive recognition commensurate with it's impact. And paying down technical debt is the definition of unsexy work.
If the company is tech savvy enough (and it doesn't seem like it is), work with stakeholders ahead of time to define key metrics and how they are impacting the bottom line of the business. Then, get everyone to agree on what the current values for all key metrics are and try and establish goals & milestones you are shooting for.
eg: Time to deploy a release right now is 5 hours. This impacts the business because developers are unable to push out changes in an agile manner so currently, we release every 3 weeks. I propose to reduce deployment down to less than 15 minutes such that we can aim for 3 releases a week. This has business value because it allows us to respond to customer complaints in an agile manner and empowers developers to build experimental features that might end up turning into major business units. The value to the business in terms of increased customer satisfaction and more innovative development is <you have to fill this in yourself>
If you don't do this, you risk devoting blood, sweat and tears to a project which, once you've completed it, everyone forgets how painful the old system was and assumes that it was always this way.