Use the replace commands to quickly replace library parts with different parts. You can replace a single instance of a part or you can replace every instance of a part. For example, if you have six screws of type A, and you need to replace them with type B, you can replace all the screws in a single step.
If you update a part in the database with a new version, you can update library parts. Use update in this situation instead of replace.
To replace a library part,
1. Click Part Library and then, in the Catalog group, click the arrow next to Modify.
2. Click Single or Shares in the Replace section.
3. Click Target part and select the part in the viewport or Structure Browser. If you are replacing all instances of a part, just select one of the parts. All instances of the same part will be replaced.
4. Click Source part and select the new part from the parts browser.
1. Click Part Library and then, in the Catalog group, click the arrow next to More.
2. Click StandardParts in the Update section. The Update dialog box opens.
3. Select All to update all parts with the latest versions.
4. Select StartAssy to select an assembly whose parts will be updated. This will update all parts in this assembly and its sub-assemblies, but no other parts will be updated.
Modify.
Single or 
Shares in the Replace section.
to complete the operation.
StandardParts in the Update section. The Update dialog box opens.