Are you running PostgreSQL ThingWorx? For PostgreSQL you could try with:
1. Using pgAdmin III or psql, connect to the ThingWorx database with the ThingWorx DB user password .If necessary, the database username and password can be retrieved from the platform-settings.json file located in the /ThingworxPlatform directory on the ThingWorx server.
2. Run the following SQL statement:
UPDATE user_model SET "passwordHash" = '100000:ecbad5a6dc172f92cddd4743e6b4877724e0c675e6e2fc1c780ab62a2350f115acdbd3c6c582afd297a4c77fb5420520e3f36c2c5e12dbfc5fc9c4f3fc2d616d:6fd6785de35b500fb633ab13be4207dead6c26f922b32610c135f446fea2d4abbce57be9058457cddd4e3944fcf42b804c29dc8939a3c29ca6ac64001d0a982c' WHERE name = 'Administrator';
In my example, the password will be "admin"
But this is just for some urgent case and you have no other choice. Directly changing database is not advised.