Will it be a straight swap?
Likely not, they very rarely are, it is different type of fitting. You will need the correct depth for the fitting, this will include a ventilation gap above and around it. The product depth is spec at 110mm, you will likely need another 25mm-50mm above that.
There is always the likelihood of joists and noggins obstructing the area, then there is also other services to consider such as pipework, electrical and data cables.
If the void is insulated, that can also be an issue, as the fittings require ventilation and to do this, you will compromise any heat loss or soundproofing qualities.
Then there is also the configuration of the existing cables and whether there is enough slack in the cable to complete a satisfactory install.
There are a number of regulation regarding downlights that need to be accomplished, also there are regulations on cable selection, jointing and exposed cable insulation that often gets ignored.
Test equipment is always an essential when doing electrical work.
You will need a holesaw(87mm) and arbour or a padsaw may do it, you may have to lift the flooring above the location, you may need some extra cabling, joint boxes, possible maintenance free ones!
I assume you have adequate insulated tools and I would suggest dust mask and safety specs.
I've changed loads of lights fittings in the past, but always like for like.
A venture into the great unknown then, it is impossible to say what obstruction and difficulties you may come across, I have tried to make you aware of the situations I have found myself in. But there is one other thing that may just prevent you from installing this fitting. Is there an CPC/earth existing in your lighting system, one that that is continuous and gives a fault path to the origins of the earthing arrangement???? This fitting will likely require that.
Do I need a transformer of any type?
No
The specification is here
http://www.screwfix.com/p/enlite-fi...rm=58258#product_additional_details_container
