As others have said "dealing with it" can include a number of different options. I would imagine one of the first issues to be considered by a Labour government would be the interest paid on loans, which was originally set at, I believe, 1.25%.
The Telegraph reported in April 2017:
"Students are facing a 33pc rise in the interest rates they accrue on their loans as a result of rising inflation......
" ..........Under rules introduced in 2012, annual interest of RPI plus 3pc is charged on student loans as they are built up while studying.
".... Based on inflation in March last year, interest is currently accruing at up to 4.6pc, meaning September’s rise will be equivalent to a 33pc increase.
"The latest increase to the interest rate means someone with a £40,000 debt would have to be paid just over £48,000 a year before they earned enough to pay off the loan rather than simply service the interest. Under the current rate, the same person would have had to earn £43,000."
In my view, the above demonstrates how ridiculously unrealistic it is to expect the majority of students to be able to pay off their substantial debts. This seems to be borne out by an article in the Financial Times in July 2016:
"About 70 per cent of students who left university last year are expected never to finish repaying their loans, according to modelling carried out by the Institute for Fiscal Studies.......
"This is in stark contrast to earlier generations of students. Of those who graduated in 2002, 44 per cent had already paid off their loan within 13 years, according to new data from the Student Loans Company.....
"This means that — for the 70 per cent of new graduates not expected to finish repaying — the loan repayments act more like an additional tax on their income above £21,000, which will last until they reach their early 50s....." ....
It must surely be a drain on morale and aspiration to be saddled with such huge debts. I would suggest that such a low degree of recovery indicates not only that the system is not working but that it is damaging the economic wellbeing and social cohesion of the country as a whole. I imagine that Corbyn has similar thoughts and saying he would deal with it may can be interpreted as he and his colleagues reaching a radical solution to this problem which, along with reducing the interest payable, might also mean reducing debts to a more manageable level, rather than scrapping them all together.
In any event, no undertaking was given to cancel debts and if some students who voted Labour did so purely on the issue of fees/loans and now feel they were misled, then presumably they won't vote Labour at the next election. It's up to them but I am cautiously optimistic that at least some of them will reflect on
what has happened since 2010 in relation to the education, health and justice systems and in relation to the housing crisis.