There ya go...
From 1957 to 2003 management of the island was delegated to Scottish Natural Heritage (SNH) and was managed under a partnership agreement between the NTS, SNH and the MoD. This changed in September 2003 when the Trust was granted ‘Approved Status’ by SNH to manage the National Nature Reserve directly.
The partnership approach to managing the islands continues, and has been expanded to include Historic Scotland, QinetiQ (agents for MoD) and Comhairle nan Eilean Siar – the Western Isles Council. Representatives of all the partnership organisations meet regularly to make both strategic and operational decisions about the management of St. Kilda. The Trust also appoints a seasonal ranger and an archaeologist, with financial assistance from SNH and Historic Scotland respectively.
Under the enabling legislation, the Trust ensures there are opportunities for access to and enjoyment of its properties by the public where possible. Given the difficulty in getting to St Kilda, the Trust provides opportunities for access through its work party
programme. Other visitors to the islands arriving by their own means are welcome, although numbers must be monitored because of the sensitivity of the natural and cultural heritage of the islands, and management carried out where necessary to ensure impacts on the heritage of the islands are minimised. The Trust is also working to provide opportunities for greater understanding and appreciation of St Kilda, not only for those who reach the islands, but also for the wider population who may not be able to visit.
For information on all aspects of St Kilda not addressed by this website, please contact:
The National Trust for Scotland
Western Isles Manager
40 Huntly Street
Tel: 01463 232 034
I guess you'll now need to apply to HTS as Polwart suggests.