Sam.The short answer is "very carefully".
If you place the sofa on its back you should be able to see how it is fastened together.You will need to study this carefully before taking it apart.Most recliner sofas/chairs are bolted/screwed to the arm sections and can be dismantled and removed.You will need to find the fastenings which are doing this job and one by one,take them out.Be very careful to note which fastenings have come from where by laying the parts out on a table or floor or marking each one both on bolt/screw and the area they were removed from.You may also need to unfasten or remove some of the upholstery so this also wil need to be done very carefully.Assuming you intent to put everything back together,the material needs to be as good a condition as it was originally.
Hope this helps.
john howden
September 2009