You can remove the assembly from the GAC by running AseGacUtility or by using the .NET Framework Configuration tool.
Removing the assembly by running AseGacUtility
Go to the directory where AseGacUtility is installed—by default C:\Sybase\DataAccess\ADONET\dll for Adaptive Server ADO.NET Data Provider, 32-bit and C:\Sybase\DataAccess64\ADONET\dll for Adaptive Server ADO.NET Data Provider, 64-bit.
Run:
AseGacUtility /u DLL_Name
where DLL_Name is the DLL you want to remove from the GAC.
For example, to remove Sybase.AdoNet2.AseClient.dll from the GAC, enter:
AseGacUtility /u c:\mango\build\bin\Sybase.AdoNet2.AseClient.dll
Removing the assembly using the .NET Framework
Configuration too
Start the .NET Framework Configuration tool. Refer to the Microsoft documentation for your specific operating system for instructions on how to start the configuration tool.
Select Assembly Cache from the tree view on the left.
Click the View List of Assemblies in the Assembly Cache link.
Find Sybase.AdoNet2.AseClient from the list of assembly names. There may be multiple entries of this assembly corresponding to various versions deployed on this system.
Select one or more assemblies to remove. Right-click and select Delete. Click Yes to confirm.
Check for the publisher policy files that correspond to the versions removed and remove these files too.
The GAC stores references made by other assemblies to
a given assembly and you cannot delete the given assembly until
these references are removed. You can force these references to
be removed as part of the delete command. On some systems, the utility
might fail to delete the assembly and complain about a pending reference
to the Windows Installer. This happens due to some residual values
in the registry. Contact Microsoft support for a resolution to this
problem.