The chains are provided in the ascii files chain_{N}.txt with N=1..12. The file format is compatible with COSMOMC and its plotting utility, getdist.
The format of each line in these files is as follows:
Column 1: weight of the point
Column 2: -ln(Likelihood)
Columns 3+: values of the parameters as specified in chain.paramnames.
Note that it is important to propagate the weight of each point in the calculation of posterior probability distributions. The chains still contain the 'burn-in'; the first 30% of entries should be removed to obtain a fair sample of the posterior.