Hello Liz,
Are we talking leisure battery here ?
Or do you have a Hybrid ?
Presumably you have ordered the same capacity, Amp per Hour (Ah); that the battery is the same physical size; and that the terminals are in the correct configuration.
The main battery will be under the bonnet in the engine bay.
If you are changing your Hybrid, there are some threads on here.
But I expect a member will be able to advise when they read your topic.
If you are changing your main battery is is quite easy, but they are heavy.
Let us know and we can tell you the correct order for disconnection and reconnection
Whichever battery you are changing; make sure you have all the correct spanners before you start !