Here is a good description of what is involved in a typical English pronunciation (or accent reduction) class or coaching program.  Things are usually tailored to the particular English level, industry or work etc. but the main idea is explained clearly here:

English language pronunciation includes all the mechanical functions and skills of language sound production and the specific word pronunciation patterns of the English language in context.
The mechanical functions and skills include placement of the lips, tongue, use of teeth, glottis, expanding or contracting the mouth cavity, use of nasal passages and soft palate, vocal folds, controlling the intake and outflow of air, devoicing, breathing and timing.

English language pronunciation class skills and exercises include initial consonant and vowel pronunciation, syllable pronunciation, individual syllable stress patterns, diphthongs and consonant clusters, initial word pronunciation, syllable stress patterns in words, intonation and timing for words, phrases, clauses, complete sentences, expressions and interjections.

English language pronunciation class can take the form of individual drills or group drills by listening and repeating the correct English language pronunciation exercises.

English language pronunciation class can take the form of reading and speaking. Students are expected to read and speak aloud correctly pronouncing each of the words or passages.

Advanced English language pronunciation classes can include accent reduction. Accent reduction can be ‘un-learning’ incorrect pronunciation and re-learning correct English pronunciation. Accent reduction can also be the initial establishment or correction of pronunciation patterns, speed, timing, stress and intonation.

From the original site  http://www.eslincanada.com