Awhile back, Wizards of the Coast announced that at some point before spring, they would release an official conversion guide to aid in converting older edition modules and adventures to be compatible with 5th Edition. Spring is here and the conversion guide has yet to be made available.
It turns out that the reason for the delay is simply that the person who needs to do the final approvals on the guide before release has been called to jury duty, and that the case he’s involved with could last another 4 months or even longer.
Escapist Game Magazine has more details with quotes about the situation from Mike Mearls at http://www.escapistmagazine.com/news/view/140183-Dungeons-Dragons-Conversion-Documents-Delayed-Due-To-Jury-Duty
So it sounds like it will still be some time before we have an official conversion guide. In the meantime, you can still do some basic conversions of your own following the guidelines posted in this article.