Unzip the two libs so visible in control panel.
Open IC.lbr from control panel.
Expand IC_LINEAR.lbr so devices visibile.
Drag TLV2372 from IC_LINEAR to open IC library.
Save IC.lbr and close.
Now try to open IC.lbr and get the following error:
Loading C:/Users/Todd/Documents/Eagle_Projects/Design_Support/Library/ICs.lbr ...
Error:
line 2554, column 9: redefinition of name 'OPAMP' in tag <symbol>
Open IC.lbr file in text editor and go to line 2554. From this line on down thru the /symbol section of XML file, all symbol names have been overwritten by symbol name OP_AMP which was the symbol name of the TLV2372 and was also present in IC.lbr. Copy from LINEAR lib to IC lib gave no warning of duplicate symbol name. Library is now corrupt and will obviously not work. Got to directory, delete IC.lbr file and rename library backup file created when you saved IC.lbr and repeat this process to see it happen again....