The communication paints the picture of a rather successful process, without major problems.
I'd just like to quote some parts of the document I find relevant and noteworthy (bold headlines are my formulations):
Conclusions for future changeovers
"In order to speed up the changeover and thus reduce the burden put on retailers who have to handle two currencies simultaneously, the change should be given exclusively in euro as of 1 January. It could be considered for future changeovers to introduce a legal prohibition on the use of the legacy currency for giving change (with an exception for cases where it is materially impossible to use the euro)."
As regards inflation
"Provisional calculations estimate the total (one-off) impact of the changeover on headline inflation during and immediately after the changeover to be within the range of up to 0.3 percentage points"
"January data from the Commission's Consumer Survey show that inflation perceptions have not been affected by the changeover. Perceived inflation remained on its downward trend and reached 21.7 pp in January, down from 25.6 pp in December. In February, perceived inflation went down further, to 18.7 pp. In the context of declining HICP inflation, it is indeed more difficult to disentangle the impact of the euro changeover on inflation perceptions."
The implication of the Commission in the information campaign and the results
"The communication campaign on the introduction of the euro started in 2007 with the launch of a national euro website and free telephone help line and the organisation of seminars and conferences. A fully fletched communication campaign started in spring 2008. [...]
It was supported by a massive distribution of publications and euro calculators to all households, a constantly updated (and massively visited) website, specialised projects for schools and journalists, a train-the-trainers programme and a 'Euromobile' bringing up to date information to remote areas. [...]
The Commission supported the campaign in technical and financial terms. This included the provision of publications and promotional material, the organisation of exhibitions, seminars for journalists and opinion polls. Via several grants, the Commission financed a part of the salaries of communication staff, the media campaign, the national help line and website, the project for schools, the programs for multipliers, the euro calculators and the 'Euromobile'. [...]
When asked about persisting information needs [in the January 2009 Eurobarometer; JF], some 31 % of Slovaks wished to learn more about the security features of euro banknotes and coins (4 in 10 respondents could not name any security feature at the time of the survey), 22% wanted to know more about fair rounding of prices while 19% wished to have more information on how to avoid being cheated in the currency conversions."