The obvious way up Skregbeg is to start at the "Hydro road" at around V77198706 A. As of spring 2012 a new car park is under construction here.
Ascend this steep concreted road in an easterly direction until it turns abruptly southwards at V7774 8690 B. From here head 1km at around 60 degress (Grid) towards Skregbeg. This takes you over an unusual ridge of perhaps 15m height, probably some type of moraine. Ascend straight up Skregbeg which as of 2012 had mostly burnt vegetation. This ascent should take about an hour.
The top of Skregbeg has great views of the eastern end of the Reeks and other parts of the Iveragh peninsula such as the Glenbeigh Horseshoe. Linkback: https://mountainviews.ie/summit/321/comment/5081/

From most vantage points in East and Mid Kerry, this minor summit delineates the western edge of the Reeks, being visible all the way to the county bounds. Inspired by madfrankie's instructions below, and being assured by the BBC weather projection of a gap in the weather, we struck off up the Hydro Road at 11.10 on 31st October 2011. We veered off to the left at the point that the hydro road turns right at V777 868 C, heading diagonally or north east up fairly rough and rocky ground. After a short haul, we reached the top of the first ridge, an excellent example of a moraine. Between this and the saddle connecting Skregbeg to her taller cousins, lies a very wet and swampy area, with care being needed in fording the swollen streams. No sooner were we onto solid ground than we were drenched by the last cold and gusty shower of the morning. Having gained the saddle, we headed left and dripping wet towards the rocky summit. A cairn lies at the top, partially overgrown with grass, possibly indicating a prehistoric origin. The views are excellent out to Dingle Bay and across the Plains of Magh O gCoinchinn (latterday barony of Magunihy), the ancient 'tuath' that stretched from the source of the Blackwater to Castlemaine harbour. Overall around two hours and twenty minutes. Linkback: https://mountainviews.ie/summit/321/comment/6636/

Dwarfed by it's more frequented neighbours, this is nevertheless a tempting diversion if you're doing the Coumloughra Circuit.
When the steep Hydro Road swings right, continue NE. There's a small loss of height before making the steepish ascent to the summit, with it's small cairn. From here you can descend to a saddle and the steep ascent to big brother Skregmore. Linkback: https://mountainviews.ie/summit/321/comment/2306/

On the Coumloughra Horseshoe I took this photo from the summit of Skregmore looking down to the speckled back of Skregbeg. Linkback: https://mountainviews.ie/summit/321/comment/1816/