Applying for further leave to remain on a spouse visa in the UK is straight forward. Or so it would seem. The only complication I can see, bar the minimum income requirement, is the need to pass a language competency test.
This requires an A2 Listening and Understanding test which can be taken with four approved providers:
IELTS SELT Consortium
Trinity College London
There are tutorials on You Tube
Apparently you can also sit for a B1 test, which if passed, can be used when it comes time to apply for indefinite leave to remain.