Take A-395 from Ronda Sur (ring road) of Granada and drive up to the ski station of Sierra Nevada. Turn left taking the road to the parking near Albergue Universitario (2.550 m). You could go by bus (Bonal) from Granada too. Walk up as said in the Normal Route, following the road and taking some shorcuts when in Cauchiles (the road does many curves). Reach Posiciones del Veleta (1h 30 min) and the "mirador" over Corral del Veleta. For reaching the summit of Veleta (2h 10 min), traverse on the ridge or the W face if climbing with a snowed ground. Descend to Refugio Vivac de la Carihuela (3.200 m, 2h 30 min), placed on the SW slope of Veleta, just where it joins to Tajos del Nevero. You could sleep here if you have started hiking late, it is non guarded.
From the Carihuela hut take "carril", wich is a wide forest (there is no forest) trail that once permited vehicles to cross the Sierra. Leave Laguna de Aguas Verdes (3.050 m) to the right and bottom. The trail traverses on the base of Cerro de los Macho. Reach Collado del Lobo, follow to the left of Laguna de Río Seco, leaving Crestones de Río Seco to the north (3h 45 min). Then take an ascending path to the left, that leaves Puntal de la Laguna Larga (3.180 m) to the north. Reach Laguna de la Caldera and Refugio Vivac de la Caldera (3.100 m). Take a trail to left, wich goes to Collado del Ciervo, then ascend in a long and steep slope to the top of Mulhacén (4h 45 min without breaks). In winter, due to a risky descent to Laguna de la Caldera, follow "carril" from Crestones de Río Seco, surround Loma Pelá and reach the Caldera hut.
The descent is on the same route if leaving your vehicle on Albergue Universitario or on the "Route from Capileira". You could pass night in Refugio Vivac de la Caldera (non guarded) or in Refugio de Poqueira (2.500 m).
From July to September is a hot season for hiking on Sierra Nevada, so if you don't have other chances take many liters of water with you because all the streams will be dry and only could remain some little snow patches (early July). Also take a cap and warm clothes for passing the nights. In winter, take care with the snow storms and be informed of the weather and avalanches before departing. Carry warm clothers, gloves, balaclava, good boots, crampons, ice axe (poles), map and compass. You could also take your mountaineering skis with you or snowshoes if the snow is soft. Try to avoid the bad days and be careful with the early storms of the autumn too.