You cannot update from SmartConnect 10.0.0.51 to 2014. You need to update to either SmartConnect 2010, 2011, or 2012 first.
The steps to update to 2014 would be as follows.
1. Run the system maintenance on your 10.0.0051 version of SmartConnect (Tools – SmartConnect – System Maintenance). You need to do it in each company because the maps are company specific in each database.
2. Download and install SmartConnect 2012 from here SmartConnect 2012
3. Follow the update instructions starting at section 18.104.22.168 Upgrading SmartConnect on page 27 of the SmartConnect 2012 manual.
4. After getting SmartConnect update to 2012, then go ahead and update to SmartConnect 2014 Installer
5. Follow the update instructions in the 2014 manual which is online and can be accessed at this link. SmartConnect 2014 Update Instructions. Ignore the section that talks about updating from 10.00.0051 since you already updated to SmartConnect 2012.