You might try wiping the cache partition, since my understanding is that downloaded apk files are cached there. No personal data will be erased.
1. From a powered off state, press and hold Power and Vol Down together until you see the Fastboot menu.
2. Use the Volume buttons to select Recovery Mode, then Power to enter it.
3. When you see the Android with its chest open, press and hold Power, then tap Vol Up, then release both buttons at the same time.
4. Use the Volume buttons to highlight Wipe Cache Partition, then Power to execute.
5. When complete, select Reboot System Now.